1. join() 將數(shù)組拼接成字符串；

var a = [1,2,4,5];

var b = a.join()

console.log(b)// '1245'

2. split() 將字符串拆分為數(shù)組；

var a = 'hello timy'

var b = a.split();

console.log(b)；//["h", "e", "l", "l", "o", " ", "t", "i", "m", "y"]

*join()與split()屬于逆向轉(zhuǎn)換；

3. reverse() 將數(shù)組中的元素順序顛倒；

var a = [1,2,3];

a.reverse();

console.log(a);//[3,2,1]

4. sort() 將數(shù)組中的元素排序并返回排序后的數(shù)組；

var a = ['cde','bed','abc'];

a.sort();

console.log(a);//["abc", "bed", "cde"]

如果數(shù)組中包含undefined元素，它們會(huì)排到數(shù)組尾部；

默認(rèn)按字母表順序；

var a = [33,4,111,22];

a.sort();

console.log(a);//[111, 22, 33, 4]

從小到大排列

a.sort(function(a,b){return a-b});

console.log(a);//[4, 22, 33, 111]

從大到小排列

a.sort(function(a,b){return b-a});

console.log(a);//[111, 33, 22, 4]

區(qū)分大小寫的排序；

a = ['ant','Bug','cat','Dog'];

a.sort();

console.log(a);//["Bug", "Dog", "ant", "cat"]

不區(qū)分大小寫的排序；

a.sort(function(s,t){

var a = s.toLowerCase();

var b = t.toLowerCase();

if(a<b) return -1;

if(a>b) return 1;

return 0;

});

console.log(a);//["ant", "Bug", "cat", "Dog"]

5. concat() 創(chuàng)建并返回一個(gè)新數(shù)組；不改變數(shù)組，用完就釋放了；

var a = [1,2,3];

a.concat(4,5); //[1,2,3,4,5]

console.log(a);//[1,2,3];

a.concat([4,5]);//[1,2,3,4,5]

a.concat([4,5],[6,7]);//[1,2,3,4,5,6,7]

a.concat(4,[5,[6,7]]);//[1,2,3,4,5,[6,7]

6. slice() 指定數(shù)組的一個(gè)片段或子數(shù)組；它的兩個(gè)參數(shù)分別是片段的開始和結(jié)束；不改變數(shù)組，用完就釋放；

var a = [1,2,3,4,5];

a.slice(0,3);//[1,2,3]

a.slice(3);//[4,5];

a.slice(1,-1);//[2,3,4];

a,slice(-3,-2);//[3]

console.log(a);// [1,2,3,4,5]

7. splice() 在數(shù)組中插入或刪除元素的通用方法；會(huì)修改數(shù)組；第一個(gè)參數(shù)表示開始截取位置，二個(gè)參數(shù)表示截取數(shù)量；還有多位參數(shù)看下面例子；

var a = [1,2,3,4,5,6,7,8,9];

var b = a.splice(4);;//[5,6,7,8,9];

console.log(a);//[1,2,3,4]

var c = a.splice(1,2);//[2,3];

console.log(a);//[1,4]

var d = a.splice(1,1);//[4]

console.log(a);//[1]

既然能刪除，當(dāng)然還會(huì)有插入；第一個(gè)參數(shù)表示插入位置，第二個(gè)參數(shù)表示替換幾位；后面的參數(shù)

var a = [1,2,3,4,5];

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

a.splice(3,3,6,7,8,9); //[1, 2, "a", 6, 7, 8, 9, 4, 5]

a.splice(3,0,[2,3,4]);//[1, 2, "a", [2,3,4], 6, 7, 8, 9, 4, 5]

注意：與concat()不同的,splice()會(huì)插入數(shù)組本身而非數(shù)組的元素

8. push() 和pop()，在數(shù)組的尾部添加一個(gè)或多個(gè)元素，刪除最后一個(gè)元素；

var a = [];

a.push(1,2);

console.log(a);//[1,2]

a.push('a','b');

console.log(a);//[1,2,'a','b']

a.pop();

console.log(a);//[1, 3, "a"]

9. unshift() 和 shift() ,在數(shù)組的頭部添加一個(gè)或多個(gè)元素，刪除一個(gè)元素；

var a = [2,3];

a.unshift(1);

console.log(a);//[1,2,3];

a.unshift('a','b');

console.log(a);//["a", "b", 1, 2, 3]

a.shift();

console.log(a);//["b", 1, 2, 3]

10. toString() 和 toLocaleString()

var a = ["b", 1, 2, 3]

var b = a.toString();

var c = a.toLocaleString();

console.log(a);//["b", 1, 2, 3]

console.log(b);//b,1,2,3

console.log(c);//b,1,2,3