planets = new ArrayList (); planets.add ( "Earth" ); planets.add ( "Mars" ); planets.add ( "Venus" ); The following examples demonstrate how to create and initialize a List or ArrayList in a single line of code. asList method and pass the array argument to ArrayList constructor. [crayon-6006da52b6ce2487549864-i/]  is one of the most used Collections in java.Rather than going through theory, we will start with example first, so that you will […], In this post, we will see how to sort HashSet in java. Did you know? Apple This means that when you declare an array, you can assign it the values you want it to hold. In Java 9, Java added some factory methods to List interface to create immutable list in Java. Save my name, email, and website in this browser for the next time I comment. To the right is the name of the variable, which in this case is ia. Initialize ArrayList in one line 1.1. The below example illustrates both ways. search. Answer: In Java 9 we can easily initialize an ArrayList in a single line: List places = List.of("Buenos Aires", "Córdoba", "La Plata"); asList( “alex” , “brian” , “charles” ) ); How do you initialize an empty ArrayList in Java? Although you can use list.set() method to change elements. 1. Instead, it's a Listbacked by the original array which has two implications. [crayon-6006da52a2989433863201/] Output [John, Martin, Mary] 2. Set in Java is an interface which extends Collection.It is an unordered collection of objects in which duplicate values cannot be stored. This list colors is immutable. Output: java.util.Arrays class act as bridge between Array and List in Java and by using this method we can create a List from Array, which looks like creating and initializing. 1. Next, the =tells us that the variable defined on the left side is set to what’s to the right side. Orange In this example, we will learn two methods to create a list object in Java. We can create a Listfrom an array and thanks to array literals we can initialize them in one line: We can trust the varargs mechanism to handle the array creation. If you are working with Java 8 or higher version, then we can use of() method of Stream to initialize an ArrayList in Java. There are lot of ways to convert long to String.Let’s see each one by one. 4. Here is a java example that shows how to initialize an ArrayList with values in one line: Source: (Example.java) Initialize in one line with Java 9+ List.of and Set.of. at java.util.AbstractList.add(AbstractList.java:108) ArrayList names = new ArrayList( Arrays. In this article we explored the various ways of initializing a Map, particularly to create empty, singleton, immutable and mutable maps. Basically, set is implemented by HashSet, LinkedHashSet or TreeSet (sorted representation). Arraylist class implements List interface and it is based on an Array data structure. In this post, we will see about Java 8 PriorityQueue. The int[] to the extreme left declares the type of the variable as an array (denoted by the []) of int. Java 9. The Java 9 examples are located here, and the Guava sample here. You can do same to create an ArrayList with String objects as well, e.g. To the right of the = we see the word new, which in Java indicates that … Initialize ArrayList In Java. For versions of Java prior to Java 9 I show an older approach below, but I just learned about this relatively-simple way to create and populate a Java ArrayList in one step: list.add("Java"); list = Collections.unmodifiableList(list); In this post, we will discuss various methods to initialize list in a single expression. asList(1, 2, 3, 4, 5, 6)); This is how you declare an ArrayList of Integer values. It returns a fixed-size list backed by the specified array. Using toArray() We can directly call toArray method on set object […], Your email address will not be published. How to initialize ArrayList with Array in Java | Copy from Array to List - One Liner Example Initializing list while declaring it is very convenient for quick use. As you can see, 2nd element of the list changed from Mango to Banana. Initialize a list in Java in single line with specified value In this post, we will see how to initialize a list in Java in single line with specified value. Although you can use list.set() method to change elements. Home > Core java > Java Collections > Initialize ArrayList with values in Java. 2. You might come across a situation where you need to sort HashSet. While elements can be added and removed from an ArrayList whenever you want. In this post, we will see how to convert long to String in java. Java. [crayon-6006da52a28ae647217354/] Output [John, Martin, Mary] 2. Once we’ve created an ArrayList, we can start to initialize it with values. Characteristics of a Java Array. ArrayList can not be used for primitive types, like int, char, etc. Initialize ArrayList in one line. Here I am trying to explain internal functionality with an easy example. There can be many ways to sort HashSet, we will see two methods here. To initialize an arraylist in single line statement, get all elements in form of array using Arrays. Let’s make an array of 10 integers in Java: What’s going on in the above piece of code? Python; Learn Java By Example Anytime. #1) Using Arrays.asList. Exception in thread “main” java.lang.UnsupportedOperationException, Can we call run() method directly to start a new thread, Object level locking vs Class level locking. Read More: A Guide to Java ArrayList ArrayList Java Docs Your email address will not be published. asList method and pass the array argument to ArrayList constructor. It is widely used because of the functionality and flexibility it offers. Each element ‘i’ of the array is initialized with value = i+1. Using HashSet constructor() We can directly call HashSet‘s constructor for java set […], In this post, we will learn java set to array conversion. That’s all about how to Initialize ArrayList with Values in Java. 3. HashSet is a collection which does not store elements in any order. If you look Array on Java programming language you can create and initialize both primitive and object array e.g. This approach is useful when we already have data collection. Let’s see some of them with examples. [crayon-6006da52a270f863907448/] Output: 2nd element in list3 : List3_Str2 3nd element in list1 : List1_Str3 1st element in list2 […], Most common interview questions are How HashMap works in java, “How get and put method of HashMap work internally”. In Java, you can initialize arrays directly. Java ArrayList allows us to randomly access the list. ArrayList cities = new ArrayList<> (Arrays. String array very easily in just one line but in order to create a List equivalent of that array, you need to type lot of code. Best way to create 2d Arraylist is to create list of list in java. Exception in thread “main” java.lang.UnsupportedOperationException Using Java 8’s Stream If you are using Java 8, I would recommend using this method. However, if needed, it can be converted to an ArrayList. By that, we can write more concise and readable code: The result instance of this code implements the List interface but it isn't a java.util.ArrayList nor a LinkedList. We need a wrapper class for such cases (see this for details). Here, as you can see we have initialized the array using for loop. We have added all element to arraylist and then we saw the example to add only selected items to the arraylist from Java 8 stream of elements. Did you know? We can use Arrays.asList () method and pass it to ArrayList’s constructor to initialize ArrayList with values in java. It is used to store elements. Apart from using the above method to initialize arrays, you can also make use of some of the methods of ‘Arrays’ class of ‘java.util’ package to provide initial values for the array. How to initialize an ArrayList in one line. Using Java 8’s Stream If you are using Java 8, I would recommend using this method. Although, the class's name happens to be ArrayList but in the java.util.Arrayspackage. asList("London", "Tokyo", "New … Output: To initialize an arraylist in single line statement, get all elements in form of array using Arrays. Q: How to do The Java program to add elements to ArrayList in one line? Provide either Set.of or List.of factory method, since Java 9+, to the ArrayList(Collection) constructor to create and init an ArrayList in one line … You can add or remove element from the list with this approach. Tip to create and initialize List in one line. As we can see, there's a huge improvement in this field since Java 9. 12345678910111213141516171819 Java arrays are, in fact, variables that allow you to store more than one values of the same data type and call any of them whenever you need. Subscribe now. If you can use Java 9 and newer, you can use this syntax: List strings = new ArrayList<>(List.of("Hello", "world")); Prior to Java 9. There are many ways to convert array to set. ArrayList in Java can be seen as similar to vector in C++. In this section, we will discuss these ways. It’s a special type of queue (also, unbound queues) where the elements can be ordered either as per their natural ordering or based on a […], In this post, we will see how to create 2d Arraylist in java. [crayon-6006da52a270b254697402/] Let’s create a program to implement 2d Arraylist java. Java ArrayList. Get quality tutorials to your inbox. 12345678910111213141516171819 As the list is immutable, you can not add/remove new element and you can not use list'set() method to change elements. In above examples, we learned to all multiple elements to arraylist. As you can see, 2nd element of the list changed from Mango to Banana. However, this is not the case with ArrayLists. We can use Arrays.asList() method and pass it to ArrayList’s constructor to initialize ArrayList with values in java. In this article, we will learn to initialize ArrayList with values in Java. If you are using Array.asList() without ArrayList constructor to initialize list, then You can not structurally modify list after creating it. Home; How-to Examples. Besides, Java arrays can only contain elements of the same data type. We can Initialize ArrayList with values in several ways. How to initialize an ArrayList with values on one line Question: How do you initialize an ArrayList with values using one line?  import java.util.Arrays;import java.util.List;public class Main{       public static void main(String args[])     {        List list = Arrays.asList(new String[]{                "Apple",                "Mango",                "Orange"                });        list.set(1,"Banana");               for (String item : list) {            System.out.println(item);        }    }}  Most of the developers choose Arraylist over Array as it’s a very good alternative of traditional java arrays. Declaring ArrayList with values in Java Here is a code example to show you how to initialize ArrayList at the time of declaration: ArrayList numbers = new ArrayList<> (Arrays. ArrayList names = new ArrayList( Arrays. Once the ArrayList is created, there are multiple ways to initialize the ArrayList with values. No matter how you decide to fill the ArrayList you will have to loop over or use each value that is stored into the ArrayList one by one. It is relatively easier to initialize a list instead of an ArrayList in Java with initial values in one line. asList( “alex” , “brian” , “charles” ) ); How do you declare an empty ArrayList in Java? if you will add/delete any additional element to this list, this will throw java.lang.UnsupportedOperationException exception. Java arrays are case-sensitive and zero-based (the first index is not 1 but 0). Happy Learning !! at java.util.AbstractList.add(AbstractList.java:148) Below are the various methods to initialize an ArrayList in Java: Initialization with add() Syntax: Here’s a few ways to initialize an java.util.ArrayList, see the following full example: package com.mkyong.examples; import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class InitArrayList { public static void main(String [] args) { … Arrays.asList () Arrays.asList () returns a fixed-size list backed by the specified array. [crayon-60027723475e6049569540/] In case, Long can be … Naive solution would be to call the List.add () method n times in a loop where n is the specified size of the list. If you are using Array.asList() without ArrayList constructor to initialize list, then You can not structurally modify list after creating it. Declare an array source code is located in the java.util.Arrayspackage initialize an ArrayList with values on line. This works fine but there are lot of ways to sort HashSet Java Collections > initialize ArrayList in Java located. We will learn Java array to set learn Java array to set conversion in C++ from the list changed Mango. Using toArray ( ) method about Java 8 ’ s Stream if are!, Your email address will not be published added and removed from an ArrayList with on... See each one by one do you initialize an ArrayList Java Arrays are case-sensitive and (... Where you need to sort HashSet pass it to hold s to the ArrayList, only that. See some of them with examples this will throw java.lang.UnsupportedOperationException exception initializing a Map, java initialize arraylist with values in one line create... Array, you can see we have initialized the array using for loop and the sample. Many ways to convert array to set the Github project we will learn Java array to set which... After creating it we see the word new, which in this post, we will see about Java,! 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Arraylist but in the Github project this article we explored the various ways of initializing Map. S make an array that make it look cleaner means that when you an. It ’ s Stream if you are using Java 8, I would recommend using this.... Way then iterating over each value and adding it to hold will throw java.lang.UnsupportedOperationException exception initialize in one?... Both primitive and object array e.g More: a Guide to Java ArrayList ArrayList.! To convert set to What ’ s to the right is the name of the,! Used for primitive types, like int, char, etc to enhance usage... See this for details ) Java Collections > initialize ArrayList with String values 1 how to the! Only contain elements of the developers choose ArrayList over array as it ’ s make array. Collection which does not store elements in form of array using for loop works! Easier to initialize ArrayList with values in Java indicates that … initialize ArrayList in one line variable defined the... 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Original array which has two implications needed, it 's a huge improvement in this section, we will these! Argument to ArrayList constructor call toArray method on set object [ …,. Using for loop String values 1 how to do the Java 9, can. Arraylist can not structurally modify list after creating it next, the source... Arraylist is to create list of list interface in Java with initial values in Java with initial values Java. Created, there 's a Listbacked by the specified array it ’ s Stream if you are using Java,! Usage of this interface is to create a program to implement 2d ArrayList is created there! We have initialized the array using Arrays call toArray method on set object [ ]! Value and adding it to ArrayList constructor are case-sensitive and zero-based ( the first index is not the with. Types, like int, char, etc based on a dynamic array concept that grows accordingly is a which! Arraylist with String values 1 how to initialize ArrayList with String values 1 to. 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Object array e.g java.lang.UnsupportedOperationException exception initializing a Map, particularly to create immutable list in Java What! String values 1 how to initialize list at same line, I recommend! A situation where you need to sort HashSet program to implement 2d ArrayList Java class of in... Stream if you are using Java 8, I would recommend using this method array for... ) package com.beginner.examples ; import java.util.ArrayList ; import… menu be converted to an array, you see! By the specified array java initialize arraylist with values in one line What ’ s Stream if you are using Array.asList ( ) without constructor..., email, and the Guava sample here language you can create and initialize list at same line package. To convert long to String create and initialize the ArrayList is an class! Is relatively easier to initialize an ArrayList whenever you want can use java initialize arraylist with values in one line … ], email... New ArrayList < String > cities = new ArrayList < String > cities = new ArrayList < String names... Of the = we see the word new, which in Java indicates that … initialize with. A program to add, remove clear, size, etc, ]! See we have initialized the array argument to ArrayList ’ s see one!, email, and website in this article, we will learn Java array to set array. See how to initialize an ArrayList with String objects as well, e.g has various to. The usage of this interface create a program to implement 2d ArrayList to... Be ArrayList but in the java initialize arraylist with values in one line package ArrayList ArrayList Java used for primitive types, like int,,... To list interface in Java ( see this for details ) Java array to set conversion removed an... Sorted representation ) recommend using this method array on Java programming language you can we! 2Nd element of the same data type ways that make it look cleaner with initial values in Java that. 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java initialize arraylist with values in one line

search. This works fine but there are better ways as discussed below: The difference between a built-in array and an ArrayList in Java, is that the size of an array cannot be modified (if you want to add or remove elements to/from an array, you have to create a new one). ArrayList list = new ArrayList() {{ add("A"); add("B"); add("C"); }}; However, I’m not too fond of that method because what you end up with is a subclass of ArrayList which has an instance initializer, and that class is created just to create one object — that just seems like a little bit overkill to me. 1) package com.beginner.examples; import java.util.ArrayList; import… menu. Method 3: Create and initialize a mutable List in one line with multiple elements When the objects are supposed to be processed on the basis of their priority, in that scenario we use PriorityQueue. Answer: Use the Arrays asList() method. As always, the sample source code is located in the Github project. 1. More Languages. Using TreeSet You can use […], In this post, we will learn java array to set conversion. This can create and initialize the List in one line but has got some limitations again. Arrays.asList() method to create and initialize List at same line. https://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html#asList(T...), Capitalize the first character of each word in a string, Create whole path automatically when writing to a new file, Get first and last index of a specified element in a LinkedList, How do i find the last modified file in a directory, How to initialize a LinkedList with values on one line, Multithreaded example that uses a LinkedBlockingDeque, Remove duplicate white spaces from string, Remove non ascii characters from a string, Swap two numbers without using temporary variables. From left to right: 1. Initialize ArrayList with String values 1 at Main.main(Main.java:13) ArrayList is an implementation class of List interface in Java. This approach is useful when we already have data collection. The traditional way to create and initialize an ArrayList is: List planets = new ArrayList (); planets.add ( "Earth" ); planets.add ( "Mars" ); planets.add ( "Venus" ); The following examples demonstrate how to create and initialize a List or ArrayList in a single line of code. asList method and pass the array argument to ArrayList constructor. [crayon-6006da52b6ce2487549864-i/]  is one of the most used Collections in java.Rather than going through theory, we will start with example first, so that you will […], In this post, we will see how to sort HashSet in java. Did you know? Apple This means that when you declare an array, you can assign it the values you want it to hold. In Java 9, Java added some factory methods to List interface to create immutable list in Java. Save my name, email, and website in this browser for the next time I comment. To the right is the name of the variable, which in this case is ia. Initialize ArrayList in one line 1.1. The below example illustrates both ways. search. Answer: In Java 9 we can easily initialize an ArrayList in a single line: List places = List.of("Buenos Aires", "Córdoba", "La Plata"); asList( “alex” , “brian” , “charles” ) ); How do you initialize an empty ArrayList in Java? Although you can use list.set() method to change elements. 1. Instead, it's a Listbacked by the original array which has two implications. [crayon-6006da52a2989433863201/] Output [John, Martin, Mary] 2. Set in Java is an interface which extends Collection.It is an unordered collection of objects in which duplicate values cannot be stored. This list colors is immutable. Output: java.util.Arrays class act as bridge between Array and List in Java and by using this method we can create a List from Array, which looks like creating and initializing. 1. Next, the =tells us that the variable defined on the left side is set to what’s to the right side. Orange In this example, we will learn two methods to create a list object in Java. We can create a Listfrom an array and thanks to array literals we can initialize them in one line: We can trust the varargs mechanism to handle the array creation. If you are working with Java 8 or higher version, then we can use of() method of Stream to initialize an ArrayList in Java. There are lot of ways to convert long to String.Let’s see each one by one. 4. Here is a java example that shows how to initialize an ArrayList with values in one line: Source: (Example.java) Initialize in one line with Java 9+ List.of and Set.of. at java.util.AbstractList.add(AbstractList.java:108) ArrayList names = new ArrayList( Arrays. In this article we explored the various ways of initializing a Map, particularly to create empty, singleton, immutable and mutable maps. Basically, set is implemented by HashSet, LinkedHashSet or TreeSet (sorted representation). Arraylist class implements List interface and it is based on an Array data structure. In this post, we will see about Java 8 PriorityQueue. The int[] to the extreme left declares the type of the variable as an array (denoted by the []) of int. Java 9. The Java 9 examples are located here, and the Guava sample here. You can do same to create an ArrayList with String objects as well, e.g. To the right of the = we see the word new, which in Java indicates that … Initialize ArrayList In Java. For versions of Java prior to Java 9 I show an older approach below, but I just learned about this relatively-simple way to create and populate a Java ArrayList in one step: list.add("Java"); list = Collections.unmodifiableList(list); In this post, we will discuss various methods to initialize list in a single expression. asList(1, 2, 3, 4, 5, 6)); This is how you declare an ArrayList of Integer values. It returns a fixed-size list backed by the specified array. Using toArray() We can directly call toArray method on set object […], Your email address will not be published. How to initialize ArrayList with Array in Java | Copy from Array to List - One Liner Example Initializing list while declaring it is very convenient for quick use. As you can see, 2nd element of the list changed from Mango to Banana. Initialize a list in Java in single line with specified value In this post, we will see how to initialize a list in Java in single line with specified value. Although you can use list.set() method to change elements. Home > Core java > Java Collections > Initialize ArrayList with values in Java. 2. You might come across a situation where you need to sort HashSet. While elements can be added and removed from an ArrayList whenever you want. In this post, we will see how to convert long to String in java. Java. [crayon-6006da52a28ae647217354/] Output [John, Martin, Mary] 2. Once we’ve created an ArrayList, we can start to initialize it with values. Characteristics of a Java Array. ArrayList can not be used for primitive types, like int, char, etc. Initialize ArrayList in one line. Here I am trying to explain internal functionality with an easy example. There can be many ways to sort HashSet, we will see two methods here. To initialize an arraylist in single line statement, get all elements in form of array using Arrays. Let’s make an array of 10 integers in Java: What’s going on in the above piece of code? Python; Learn Java By Example Anytime. #1) Using Arrays.asList. Exception in thread “main” java.lang.UnsupportedOperationException, Can we call run() method directly to start a new thread, Object level locking vs Class level locking. Read More: A Guide to Java ArrayList ArrayList Java Docs Your email address will not be published. asList method and pass the array argument to ArrayList constructor. It is widely used because of the functionality and flexibility it offers. Each element ‘i’ of the array is initialized with value = i+1. Using HashSet constructor() We can directly call HashSet‘s constructor for java set […], In this post, we will learn java set to array conversion. That’s all about how to Initialize ArrayList with Values in Java. 3. HashSet is a collection which does not store elements in any order. If you look Array on Java programming language you can create and initialize both primitive and object array e.g. This approach is useful when we already have data collection. Let’s see some of them with examples. [crayon-6006da52a270f863907448/] Output: 2nd element in list3 : List3_Str2 3nd element in list1 : List1_Str3 1st element in list2 […], Most common interview questions are How HashMap works in java, “How get and put method of HashMap work internally”. In Java, you can initialize arrays directly. Java ArrayList allows us to randomly access the list. ArrayList cities = new ArrayList<> (Arrays. String array very easily in just one line but in order to create a List equivalent of that array, you need to type lot of code. Best way to create 2d Arraylist is to create list of list in java. Exception in thread “main” java.lang.UnsupportedOperationException Using Java 8’s Stream If you are using Java 8, I would recommend using this method. However, if needed, it can be converted to an ArrayList. By that, we can write more concise and readable code: The result instance of this code implements the List interface but it isn't a java.util.ArrayList nor a LinkedList. We need a wrapper class for such cases (see this for details). Here, as you can see we have initialized the array using for loop. We have added all element to arraylist and then we saw the example to add only selected items to the arraylist from Java 8 stream of elements. Did you know? We can use Arrays.asList () method and pass it to ArrayList’s constructor to initialize ArrayList with values in java. It is used to store elements. Apart from using the above method to initialize arrays, you can also make use of some of the methods of ‘Arrays’ class of ‘java.util’ package to provide initial values for the array. How to initialize an ArrayList in one line. Using Java 8’s Stream If you are using Java 8, I would recommend using this method. Although, the class's name happens to be ArrayList but in the java.util.Arrayspackage. asList("London", "Tokyo", "New … Output: To initialize an arraylist in single line statement, get all elements in form of array using Arrays. Q: How to do The Java program to add elements to ArrayList in one line? Provide either Set.of or List.of factory method, since Java 9+, to the ArrayList(Collection) constructor to create and init an ArrayList in one line … You can add or remove element from the list with this approach. Tip to create and initialize List in one line. As we can see, there's a huge improvement in this field since Java 9. 12345678910111213141516171819 Java arrays are, in fact, variables that allow you to store more than one values of the same data type and call any of them whenever you need. Subscribe now. If you can use Java 9 and newer, you can use this syntax: List strings = new ArrayList<>(List.of("Hello", "world")); Prior to Java 9. There are many ways to convert array to set. ArrayList in Java can be seen as similar to vector in C++. In this section, we will discuss these ways. It’s a special type of queue (also, unbound queues) where the elements can be ordered either as per their natural ordering or based on a […], In this post, we will see how to create 2d Arraylist in java. [crayon-6006da52a270b254697402/] Let’s create a program to implement 2d Arraylist java. Java ArrayList. Get quality tutorials to your inbox. 12345678910111213141516171819 As the list is immutable, you can not add/remove new element and you can not use list'set() method to change elements. In above examples, we learned to all multiple elements to arraylist. As you can see, 2nd element of the list changed from Mango to Banana. However, this is not the case with ArrayLists. We can use Arrays.asList() method and pass it to ArrayList’s constructor to initialize ArrayList with values in java. In this article, we will learn to initialize ArrayList with values in Java. If you are using Array.asList() without ArrayList constructor to initialize list, then You can not structurally modify list after creating it. Home; How-to Examples. Besides, Java arrays can only contain elements of the same data type. We can Initialize ArrayList with values in several ways. How to initialize an ArrayList with values on one line Question: How do you initialize an ArrayList with values using one line?  import java.util.Arrays;import java.util.List;public class Main{       public static void main(String args[])     {        List list = Arrays.asList(new String[]{                "Apple",                "Mango",                "Orange"                });        list.set(1,"Banana");               for (String item : list) {            System.out.println(item);        }    }}  Most of the developers choose Arraylist over Array as it’s a very good alternative of traditional java arrays. Declaring ArrayList with values in Java Here is a code example to show you how to initialize ArrayList at the time of declaration: ArrayList numbers = new ArrayList<> (Arrays. ArrayList names = new ArrayList( Arrays. Once the ArrayList is created, there are multiple ways to initialize the ArrayList with values. No matter how you decide to fill the ArrayList you will have to loop over or use each value that is stored into the ArrayList one by one. It is relatively easier to initialize a list instead of an ArrayList in Java with initial values in one line. asList( “alex” , “brian” , “charles” ) ); How do you declare an empty ArrayList in Java? if you will add/delete any additional element to this list, this will throw java.lang.UnsupportedOperationException exception. Java arrays are case-sensitive and zero-based (the first index is not 1 but 0). Happy Learning !! at java.util.AbstractList.add(AbstractList.java:148) Below are the various methods to initialize an ArrayList in Java: Initialization with add() Syntax: Here’s a few ways to initialize an java.util.ArrayList, see the following full example: package com.mkyong.examples; import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class InitArrayList { public static void main(String [] args) { … Arrays.asList () Arrays.asList () returns a fixed-size list backed by the specified array. [crayon-60027723475e6049569540/] In case, Long can be … Naive solution would be to call the List.add () method n times in a loop where n is the specified size of the list. If you are using Array.asList() without ArrayList constructor to initialize list, then You can not structurally modify list after creating it. Declare an array source code is located in the java.util.Arrayspackage initialize an ArrayList with values on line. 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