• Object.keys(obj)返回参数obj可被枚举的属性
  • 标签 : 其他 ???来源 : 标签: object.keys js 分类: JS
  • Object.keys(obj),返回一个数组,数组里是该obj可被枚举的所有属性。请看示例:


    示例一:
    ? ? function Pasta(grain, width, shape) {
    ? ? ? ? ? ? this.grain = grain;
    ? ? ? ? ? ? this.width = width;
    ? ? ? ? ? ? this.shape = shape;
    ? ? ? ? ? ? this.toString = function () {
    ? ? ? ? ? ? ? ? ? ? return (this.grain + ", " + this.width + ", " + this.shape);
    ? ? ? ? ? ? }
    ? ? }

    ? ? console.log(Object.keys(Pasta)); //console: []
    ? ? var spaghetti = new Pasta("wheat", 0.2, "circle");
    ? ? console.log(Object.keys(spaghetti)); //console: ["grain", "width", "shape", "toString"]


    示例二:

    ? ? var arr = ["a", "b", "c"];
    ? ? console.log(Object.keys(arr)); // console: ["0", "1", "2"]


    ? ? var obj = { 0 : "a", 1 : "b", 2 : "c"};
    ? ? console.log(Object.keys(obj)); // console: ["0", "1", "2"]


    ? ? var an_obj = { 100: "a", 2: "b", 7: "c"};
    ? ? console.log(Object.keys(an_obj)); // console: ["2", "7", "100"]


    ? ? var my_obj = Object.create({}, { getFoo : { value : function () { return this.foo } } });
    ? ? my_obj.foo = 1;

    ? ? console.log(Object.keys(my_obj)); // console: ["foo"]