How to delete the element of an array by javascript

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Javascript delete several elements of the array method: 1, the use of splice (), syntax "array.splice (specified location index, 1)"; 2, the use of the delete keyword, syntax "delete array name [specified location index]".

The operating environment of this tutorial: windows7 system, javascript1.8.5 version, Dell G3 computer.

The method of deleting the element of an array by javascript

1. Using splice () method

A splice () method is provided in the Array object of JavaScript to perform specific operations on the array. Splice () is probably the most powerful array method, and it can be used in many ways. I only introduce how to delete array elements here. When deleting an array element, it can delete any number of items by specifying only two parameters: the location of the first item to delete and the number of items to delete.

Syntax for deleting an element:

Array.splice (index,howmany)

The first parameter, index, can specify the location of the starting subscript (that is, where to start deleting the element)

The second parameter, howmany, specifies the number of elements that should be deleted (that is, one or more elements to be deleted).

Let's take a look at the following examples:

Var arr=; console.log (arr); arr.splice (1pm 1); console.log (arr)

You can see that you delete 1 element from the location of subscript 1 (the second element of the array) using arr.splice (1), that is, delete arr [1], so the output is as follows:

2. Use the delete keyword

JavaScript provides a delete keyword to delete (clear) array elements.

Var colors = ["red", "blue", "grey", "green"]; delete colors [0]; console.log (colors); / / [undefined, "blue", "grey", "green"]

Note that the array length does not change after the element is deleted using delete, except that the deleted element is set to undefined.

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