How to add new elements to an array?

46 Asked by JustinStewart in Java , Asked on Sep 2, 2025

How can you add new elements to an array in different programming languages? Learn what methods like append(), push(), or direct indexing do, and how they help expand arrays efficiently.

Answered by Irene Ellison

Adding new elements to an array is a common task in programming, and the method you use depends on the language. Arrays are used to store multiple values, and most languages provide built-in functions or operators to expand them.

Here are some common ways:

In Python:

Use append() to add a single element.

 arr = [1, 2, 3]

arr.append(4)  # [1, 2, 3, 4]

Use extend() to add multiple elements.

   arr.extend([5, 6])  # [1, 2, 3, 4, 5, 6]

Use insert() to add an element at a specific position.

In [removed]

Use push() to add elements at the end.

 let arr = [1, 2, 3];

arr.push(4); // [1, 2, 3, 4]

Use unshift() to add elements at the beginning.

Use splice() to insert elements at any position.

In Java:

Arrays in Java have fixed sizes, so you can’t directly add elements. Instead, you often use ArrayList.

 ArrayList list = new ArrayList<>();

list.add(1);

list.add(2);

Key Points:

Arrays in some languages (like Python, JavaScript) are dynamic and can grow.
In static languages (like Java, C), you often use resizable structures like ArrayList or Vector.

Best Practice: Choose the right method depending on whether you’re adding a single item, multiple items, or inserting at a specific index.

How to add new elements to an array?

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