js 循环

//数组循环
var a = [1, 2, 3, 4, 5, 6];
for (var i = 0, l = a.length; i < l; i++) {
console.log(a[i]);
}

for (var i in a) {
console.log(a[i]);
}

a.forEach(function (v, i, a) {
a[i] = v + 1;
console.log(a[i]);
});

a.map(function (x) {
return x + 1
});

//枚举值的遍历

var o = {x: 1, y: 2, z: 3};
for (p in o) {
console.log(o[p]);
}