1,.length---- 获取数组长度;
- var arr = [1,2,3,4,5];
- console.log(arr.length) //5
2,shift()---- 删除原数组第一项, 并返回删除元素的值; 如果数组为空则返回 undefined, 直接在元数组上修改;
- var arr= [1,2,3,4,5];
- var result = arr.shift();
- console.log(arr) //[2,3,4,5]
- console.log(result) //1
3,unshift()---- 将参数添加到原数组开头, 并返回数组的长度, 直接在元数组上修改;
- arr = [1,2,3,4,5];
- result = arr.unshift(-2,-1);
- console.log(arr) //[-2,-1,1,2,3,4,5]
- console.log(result) //7
4,pop()---- 删除原数组最后一项, 并返回删除元素的值; 如果数组为空则返回 undefined, 直接在元数组上修改;
- arr= [1,2,3,4,5];
- result = arr.pop();
- console.log(arr) //[1,2,3,4]
- console.log(result) //5
5,push()---- 将参数添加到原数组末尾, 并返回数组的长度, 直接在元数组上修改;
- arr = [1,2,3,4,5];
- result = arr.push(6,7);
- console.log(arr) //[1,2,3,4,5,6,7]
- console.log(result) //7
6,concat()---- 数组合并, 返回一个新数组, 不影响原数组;
- arr = [1,2,3,4,5];
- result = arr.concat(6,7);
- console.log(arr); //[1,2,3,4,5]
- console.log(result); //[1,2,3,4,5,6,7]
7,sort()---- 将数组从小到大排序, 直接在原数组上修改;
- arr = [4,5,2,3,1];
- result = arr.sort();
- console.log(arr); //[1, 2, 3, 4, 5]
- console.log(result) //[1, 2, 3, 4, 5]
8,reverse()---- 将数组反序, 直接在原数组上修改;
- arr = [4,5,2,3,1];
- result = arr.reverse()
- console.log(arr); //[1, 3, 2, 5, 4]
- console.log(result) //[1, 3, 2, 5, 4]
9,slice(startIndex,endIndex)---- 截取起始索引 startIndex 到 结束索引 endIndex 之间的项组成新的数组, 该新数组包括起始索引 startIndex 所对应的项, 不包括结束索引 endIndex 所对应的项;
- arr = [1,2,3,4,5];
- result1 = arr.slice(2,5);
- result2 = arr.slice(2);
- console.log(arr) //[1,2,3,4,5]
- console.log(result1) //[3,4,5]
- console.log(result2) //[3,4,5]
10,join(separator)---- 将数组的元素组起一个字符串, 以 separator 为分隔符, 省略的话则用默认用逗号为分隔符, 不影响原数组;
- arr= [1,2,3,4,5];
- result = arr.join("|");
- console.log(arr) //[1, 2, 3, 4, 5]
- console.log(result) //1|2|3|4|5
11,splice(start,deleteCount,val1,val2,...)---- 从 start 位置开始删除 deleteCount 项, 并从该位置起插入 val1,val2,... , 直接在原数组上修改;
- arr= [1,2,3,4,5];
- result1 = arr.splice(2,2,7,8,9);
- console.log(arr); //[1,2,7,8,9,5]
- console.log(result1); //[3,4]
- result2 = arr.splice(0,1); // 同 shift
- console.log(arr); //[2,7,8,9,5]
- console.log(result2); //[1]
- arr.splice(0,0,-2,-1); // 同 unshift
- console.log(arr); //[-2,-1,2,7,8,9,5]
- result3 = arr.length;
- console.log(result3); //7
- result4 = arr.splice(arr.length-1,1); // 同 pop
- console.log(arr); //[-2,-1,2,7,8,9]
- console.log(result4); //[5]
- arr.splice(arr.length,0,6,7); // 同 push
- console.log(arr); //[-2,-1,2,7,8,9,6,7]
- result5 = arr.length;
- console.log(result5) //8
来源: http://www.bubuko.com/infodetail-2574083.html