How to use splice in js

JavaScript's Splice method allows you to delete or insert elements from an array, returning a new array containing the deleted elements. The usage is as follows: Delete elements: arr.splice(start, deleteCount) Insert elements: arr.splice(start, 0, ...items) Replace elements: arr.splice(start, 1, ...items) Delete from the end Element: arr.splice(-1, deleteCount)Delete element from the beginning: arr.splice(0, deleteCount)

Splice method in JavaScript Usage

The Splice method is a built-in method of the Array object in JavaScript, used to delete or insert elements from the array. It returns a new array containing the deleted elements, and new elements can be inserted in the original order.

Syntax

array.splice(start, deleteCount, ...items)

Parameters

• start: The starting position of deleted elements , starting from 0. If you specify a negative number, counting starts from the end of the array.
• deleteCount: The number of elements to be deleted. If not specified, it will be deleted from the starting position to the end of the array.
• items: Optional parameter used to insert new elements after deletion.

Return value

A new array containing the deleted elements.

How to remove elements using

1. :

   const arr = [1, 2, 3, 4, 5];
   arr.splice(2, 2); // [3, 4]

2. Insert element:

   arr.splice(2, 0, 'a', 'b'); // [1, 2, 'a', 'b', 3, 4, 5]

3. Replace element:
   Delete element and insert new element, which is equivalent to replacement operation:

   arr.splice(2, 1, 'c'); // [1, 2, 'c', 4, 5]

4. Remove elements from the end of the array:
   Use a negative starting position:

   arr.splice(-1, 1); // [1, 2, 'c', 4]

5. Remove elements from the beginning of the array :
   Specify the starting position as 0:

   arr.splice(0, 1); // [2, 'c', 4]

Note

• The Splice method will directly modify the original array.
• The returned array contains the deleted elements, and the original array will be modified.
• If deleteCount is less than 0 or greater than the array length, it will be ignored.
• If start is greater than the array length, no operation will be performed.
• If you want to delete and insert elements at the same time, you should use the spread operator (...) with the new element as argument.

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