How to modify an element in an array in ES6

Modification method: 1. Use the "array name [specified subscript value] = new value;" syntax, access the specified element through the subscript, and reassign the value to the element for modification; 2. Use "array .splice(start article, delete number of elements, insert value 1, insert value 2)" statement, delete n elements from the specified position and insert n new elements.

The operating environment of this tutorial: Windows 7 system, ECMAScript version 6, Dell G3 computer.

ES6 Modify an element in the array

Method 1: Access the specified element through the subscript and reassign the value

Arrays are composite data, and the array name is a reference variable pointing to the array, so the array is a reference object.

Accessing an array is accessing array elements. The elements are equivalent to variables. The elements of the array are a set of variables arranged in an orderly manner. They have no identifiers and are indexed with subscripts. The subscripts start from 0 and increase in order. Note that the array subscript is a non-negative integer expression or a character number, and cannot be other types of values ​​or expressions.

Syntax for accessing array elements and reassigning values:

数组名[指定下标值]=新值;

Example:

var arr = [1,2,3,4,5];  //声明一个数组
console.log(arr);
arr[0] = 0;  //修改第一个元素，重新赋值为0
arr[2] = "A";  //修改第三个元素，重新赋值为2
console.log(arr);

Method 2: Using the splice() method

The splice() method of Array array is also a very powerful method. Its function is: deletion, insertion, replacement

It should be noted that: The splice() method directly modifies the original array

We can use the replacement function of this method to modify the array elements.

Syntax:

array.splice(starti,n,值1，值2);

The actual is: delete n elements at the position of starti, and then insert the value 1 and the value 2 at this position, which can replace the original ones that were deleted Value

Example

var array = [1,2,3,4,5];  //声明一个数组
console.log(array);
array.splice(2,2,123,456);
console.log(array);

[Related recommendations: javascript video tutorial, web front-end 】

The above is the detailed content of How to modify an element in an array in ES6. For more information, please follow other related articles on the PHP Chinese website!