Shulou(Shulou.com)06/02 Report--

This article mainly introduces how to use the splice method in javascript, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let Xiaobian take you to understand.

The javascript splice () method can be used to delete a specified number of elements, replace a specified element, and add an element at a specified location, using the syntax "array.splice (index,count,item1,.,itemX)".

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

Javascript splice method

In javascript, the splice () method is used to add or remove elements from an array.

Syntax:

The array.splice (index,count,item1,.,itemX) parameter is required to describe index. Specifies where to add / remove elements.

This parameter is the subscript of the array element that starts to be inserted and / or deleted, and must be a number. Coun is optional. Specifies how many elements should be deleted. Must be a number, but can be "0".

If this parameter is not specified, all elements from the beginning of index to the end of the original array are deleted. Item1,..., itemX is optional. New elements to add to the array

The splice () method is more powerful, it can delete a specified number of elements, replace a specified number of elements, and add elements at a specified location. The implementation of these different functions needs to be determined by combining method parameters:

When there are only two parameters, index and count, if count is not equal to 0PowerSplice (), the deletion function is implemented and the deleted element is returned: the number of elements specified by the count parameter is deleted from the position specified by the index parameter

When the parameter is more than 3 and the count parameter is not 0, the splice () method implements the replacement function and returns the replaced element: replace the number of elements specified by the count parameter at the location specified by the index parameter with the third and subsequent parameters

When there are more than three parameters and the count parameter is 0, the implementation of the splice () method adds functionality: add the third and subsequent parameters to the location specified by the index parameter.

Return value: array type; if the element is deleted from the array, the array containing the deleted element is returned.

Examples of functions implemented by the splice () method are as follows:

① uses splice () to delete a specified number of elements from a specified location:

Var arr = ['Achievement alert (arr)]; / / 2 parameters. The second parameter is not 0 to delete the function. Alert (arr); / / returns CPowerD.

② uses splice () to replace the specified number of elements starting at the specified location with the specified element:

Var arr = ['Achievement recorder]; / / 3 parameters, the second parameter is not 0, to achieve the replacement function: replace A with a, return: Aalert (arr.splice); alert (arr); / / return: a, B, arr.splice); / / replace an and B with an or b, and return a balance (arr) / / return: an or bpm Cpene D

③ uses splice () to add the specified element at the specified location:

Var arr = ['Achievement recordings']; / / 4 parameters, the second parameter is 0, to achieve the add function: add aaa,bbb at the subscript 1, no return value alert (arr.splice (1memaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaforme BBBBBBBD)); alert (arr); / / return: Amaaaarecoverbbpjd

Example: use the splice () method to achieve array deduplication.

Using splice method to achieve array deduplication var arr = [1 var I = 0; I]

< arr.length; i++){ for(var j = i + 1; j < arr.length; j++){ if(arr[i] == arr[j]){ arr.splice(j,1);//删除 j 位置处的元素 j--; } } } alert(arr);//返回1,2,4三个元素 上述代码使用了具有两个参数的 splice()，实现了删除指定元素的功能。

Thank you for reading this article carefully. I hope the article "how to use splice in javascript" shared by the editor will be helpful to everyone. At the same time, I also hope that you will support and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.