1.shift(从第一个元素取得元素,取一个,删除数组中一个)
var l = [1, 2, 3, 4, 5]; console.log(l.shift()); console.log(l); console.log(l.shift()); console.log(l.shift()); console.log(l.shift()); console.log(l.shift()); console.log(l.shift()); console.log(l.shift()); console.log(l);
1 [ 2, 3, 4, 5 ] 2 3 4 5 undefined undefined []
2.slice 切片,也就是截取一段(不改变原始数组内容)
var l = [0, 1, 2, 3, 4, 5]; var l1 = l.slice(1); console.log(l); console.log(l1); // [ 0, 1, 2, 3, 4, 5 ] // [ 1, 2, 3, 4, 5 ] var l2 = l.slice(1, 4); console.log(l2); // [ 1, 2, 3 ]
3.indexOf 查找(找到返回位置,从0开始计数,找不到返回-1)
var l = [0, 1, 2, 3, 4]; console.log(l.indexOf(1)); // 1 console.log(l.indexOf(100)); // -1
4.push 往尾处插入 和 pop从尾部取值 (会改变数组元素)
var l = [0, 1, 2, 3, 4]; l.push(5); console.log(l); // [ 0, 1, 2, 3, 4, 5 ] var v = l.pop(); console.log(l); // [ 0, 1, 2, 3, 4 ] console.log(v); // 5
5.取得最后一个值
var l = [1,2,3,4]; console.log(l[l.length - 1]); // 4