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How-to articles, tricks, and solutions about ARRAYLIST

ArrayList of int array in java

To create an ArrayList of int arrays in Java, you can use the following syntax:

java arraylist

Best way to convert an ArrayList to a string

To convert an ArrayList to a string in Java, you can use the join method of the String class, which allows you to join the elements of the ArrayList into a single string. Here's an example of how you might do this:

java string arraylist

Convert ArrayList<String> to String[] array

To convert an ArrayList<String> to a String[] array in Java, you can use the toArray method of the ArrayList class and pass it an empty array of the appropriate type:

java arrays arraylist

Convert list to array in Java

To convert a List to an array in Java, you can use the toArray() method of the List interface. This method returns an array containing all of the elements in the list in the proper order.

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Converting 'ArrayList<String> to 'String[]' in Java

You can use the toArray() method of the ArrayList class to convert an ArrayList of strings to a string array. Here's an example:

java string arrays collections arraylist

Get specific ArrayList item

To get a specific item from an ArrayList in Java, you can use the get() method of the ArrayList class.

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How do I remove repeated elements from ArrayList?

To remove repeated elements from an ArrayList in Java, you can use the removeAll method and pass it a Collection containing the elements to be removed.

java list collections arraylist duplicates

How to convert an ArrayList containing Integers to primitive int array?

To convert an ArrayList containing Integer objects to a primitive int array in Java, you can use the toArray method and a casting operation.

java arrays arraylist primitive-types

How to count the number of occurrences of an element in a List

To count the number of occurrences of an element in a List in Java, you can use the Collections.frequency(Collection, Object) method, which returns the number of times the specified element appears in the collection.

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How to create ArrayList from array in Java

To create an ArrayList from an array in Java, you can use the ArrayList constructor that takes an Collection as an argument.

java type-conversion arrays arraylist

How to declare an ArrayList with values?

To declare an ArrayList with values in Java, you can use the Arrays.asList method and pass it an array or a list of values.

java arraylist initialization declare

How to find the length of an array list?

To find the length (number of elements) of an ArrayList in Java, you can use the size() method of the ArrayList class.

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How to get the last value of an ArrayList

To get the last value of an ArrayList in Java, you can use the size() method to get the size of the list and then access the value at the index size() - 1.

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How to Initialization of an ArrayList in one line in Java

You can initialize an ArrayList in one line in Java using the following syntax:

java collections arraylist initialization

How to sort a List/ArrayList?

To sort a List or ArrayList in Java, you can use the sort method of the Collections class from the java.util package. The sort method takes a List and sorts it in ascending order according to the natural ordering of its elements.

java list collections arraylist sorting

How to sort an ArrayList in Java

To sort an ArrayList in Java, you can use the Collections.sort method.

java collections arraylist sorting

Initial size for the ArrayList

The initial size of an ArrayList in Java is 0.

java arraylist indexoutofboundsexception

Java ArrayList copy

There are several ways to create a copy of an ArrayList in Java:

java arraylist

Java: how can I split an ArrayList in multiple small ArrayLists?

Here is an example of how you can split an ArrayList into multiple smaller ArrayLists in Java:

java arraylist

Java: How to read a text file

To read a text file in Java, you can use the BufferedReader class from the java.io package.

java arraylist file-io text-files

Remove Item from ArrayList

To remove an item from an ArrayList in Java, you can use the remove() method of the ArrayList class.

java arraylist

When to use LinkedList over ArrayList in Java?

In Java, both ArrayList and LinkedList are implementations of the List interface that allow you to store a collection of objects in a specific order. However, they are implemented differently and have different performance characteristics.

java collections arraylist linked-list

Why do I get an UnsupportedOperationException when trying to remove an element from a List?

The java.lang.UnsupportedOperationException is thrown when an operation is not supported by a class.

java list arraylist exception