JavaScript: The Definitive Guide, Sixth Editio javaScript权威指南(第6版) pdf 文字版-文字版, javascript电子书, 和javascript 有关的电子书:

Array.shift()

a = new Array(1, 2, 3); // a[0] == 1, a[2] == 3; a.reverse(); // Now a[0] == 3, a[2] == 1;


Array.shift()

shift array elements down

Synopsis

array.shift()

Returns

The former first element of the array.

Description

shift()removes and returns the first element of array, shifting all subsequent elements down one place to occupy the newly vacant space at the start of the array. If the array is empty, shift() does nothing and returns the undefined value. Note that shift() does not create a new array; instead, it modifies array directly.

shift() is similar to Array.pop(), except it operates on the beginning of an array rather than the end. shift() is often used in conjunction with unshift().

Example

var a = [1, [2,3], 4] a.shift(); // Returns 1; a = [[2,3], 4] a.shift(); // Returns [2,3]; a = [4]

See Also

Array.pop() , Array.unshift()

Array.slice()

欢迎转载,转载请注明来自一手册:http://yishouce.com/book/1/28149.html
友情链接It题库(ittiku.com)| 版权归yishouce.com所有| 友链等可联系 admin#yishouce.com|粤ICP备16001685号-1