javascript遍历json对象的key和任意js对象属性

使用 keys 方法获取该对象的属性和方法:

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

var spaghetti = new Pasta("wheat", 0.2, "circle");
var arr = Object.keys(spaghetti);
document.write(arr);结果图:



显示 Pasta 对象中以字母“g”开头的所有可枚举属性的名称:

function Pasta(grain, width, shape) {
this.grain = grain;
this.width = width;
this.shape = shape;
}

function CheckKey(value) {
var firstChar = value.substr(0, 1);
if (firstChar.toLowerCase() == "g") {
return true;
} else {
return false;
}
}

var polenta = new Pasta("corn", 1, "mush");
var keys = Object.keys(polenta).filter(CheckKey);
document.write(keys);结果如图:



遍历json对象的键:

var an_obj = { 100: 'a', 2: 'b', 7: 'c', "name": "wu", "interesting": "Game" };
document.write(Object.keys(an_obj));结果如图: