js 数组/对象/日期的浅克隆

    //封装
    function clone (obj) {
        // Handle the 3 simple types, and null or undefined
        if (null == obj || "object" != typeof obj) return obj;
        // Handle Date
        if (obj instanceof Date) {
            var copy = new Date();
            copy.setTime(obj.getTime());
            return copy;
        }
        // Handle Array
        if (obj instanceof Array) {
            var copy = [];
            for (var i = 0; i < obj.length; ++i) {
                copy[i] = clone(obj[i]);
            }
            return copy;
        }
        // Handle Object
        if (obj instanceof Object) {
            var copy = {};
            for (var attr in obj) {
                if (obj.hasOwnProperty(attr)) copy[attr] = clone(obj[attr]);
            }
            return copy;
        }
        throw new Error("Unable to copy obj! Its type isn‘t supported.");
    };
   //调用 
    var arr=[1,2,3,5];
    var aa=clone(arr);
    console.log(aa);
    console.log(arr);
    var object1={"yu":1,"yo":2} ;
    var obj1=clone(object1);
    console.log(object1);
    console.log(obj1);
    var dta=new Date();
    var qq=clone(dta);
    console.log(dta);
    console.log(qq);