js中判断Object、Array、Function等引用类型对象是否相等的方法

 js中判断Object、Array、Function等引用类型对象是否相等，引用类型无法直接使用 == 或=== 取得期待结果。

法一：需要一个迭代的compare函数转化成原始类型进行比较

function compare(a,b){ 
var pt = /undefined|number|string|boolean/, fn = /^(function\s*)(\w*\b)/, cr = "constructor", cn = "childNodes",
 pn ="parentNode", 
ce = arguments.callee; 
if(pt.test(typeof a) || pt.test(typeof b) || a === null || b === null){ 
    return a === b || (isNaN(a) && isNaN(b)); //为了方便，此处假定NaN == NaN 
} 
if(a[cr] !== b[cr]){ 
    return false; 
} 
switch(a[cr]){ 
    case Date : { 
        return a.valueOf() === b.valueOf(); 
    }; 
    case Function : { 
        return a.toString().replace(fn,'$1') === b.toString().replace(fn,'$1'); //硬编码中声明函数的方式会影响到toString的结果，因此用正则进行格式化 
    }; 
    case Array : { 
        if(a.length !== b.length){ 
            return false; 
        } 
        for(var i=0;i<a.length;i++){ 
            if(!ce(a[i],b[i])){ 
                return false; 
            } 
        } 
    break; 
    }; 
    default : { 
        var alen = 0, blen = 0, d; 
        if(a === b){ 
            return true; 
        } 
        if(a[cn] || a[pn] || b[cn] || b[pn]){ 
            return a === b; 
        } 
        for(d in a){ 
            alen++ ; 
        } 
        for(d in b){ 
            blen++; 
        } 
        if(alen !== blen){ 
            return false; 
        } 
        for(d in a){ 
            if(!ce(a[d],b[d])){ 
                return false; 
            } 
        } 
        break; 
    }; 
} 
    return true; 
} 
console.log(compare({},{a:1})); //false 
console.log(compare({a:1},{b:2})); //false 
console.log(compare({b:2,a:1},{a:1,b:2})); //true 
console.log(compare({a:function(){return false;},b:2},{a:function(){return false;},b:2})); //true 
console.log(compare([],[])); //true 
console.log(compare([2,1],[1,2])); //false 
console.log(compare(function(){alert(1)},function(){})); //false 
console.log(compare(function aaa(){alert(1)},function(){alert(1)})); //true 
console.log(compare(document.getElementsByTagName("a")[0],document.getElementsByTagName("a")[1])); //true 
console.log(compare(document.getElementsByTagName("a")[0],document.getElementsByTagName("a")[0])); //true 

法二：直接检测Array或Object的  用arguments.callee

function equal(objA, objB)
{
    if (typeof arguments[0] != typeof arguments[1])
        return false;
    console.log(arguments[0],arguments[1]);
    //数组
    if (arguments[0] instanceof Array)
    {
        if (arguments[0].length != arguments[1].length)
            return false;
        
        var allElementsEqual = true;
        for (var i = 0; i < arguments[0].length; ++i)
        {
            if (typeof arguments[0][i] != typeof arguments[1][i])
                return false;

            if (typeof arguments[0][i] == 'number' && typeof arguments[1][i] == 'number')
                allElementsEqual = (arguments[0][i] == arguments[1][i]);
            else
                allElementsEqual = arguments.callee(arguments[0][i], arguments[1][i]);            //递归判断对象是否相等                
        }
        return allElementsEqual;
    }
    
    //对象
    if (arguments[0] instanceof Object && arguments[1] instanceof Object)
    {
        var result = true;
        var attributeLengthA = 0, attributeLengthB = 0;
        for (var o in arguments[0])
        {
            //判断两个对象的同名属性是否相同（数字或字符串）
            if (typeof arguments[0][o] == 'number' || typeof arguments[0][o] == 'string')
                result = eval("arguments[0]['" + o + "'] == arguments[1]['" + o + "']");
            else {
                //如果对象的属性也是对象，则递归判断两个对象的同名属性
                //if (!arguments.callee(arguments[0][o], arguments[1][o]))
                if (!arguments.callee(eval("arguments[0]['" + o + "']"), eval("arguments[1]['" + o + "']")))
                {
                    result = false;
                    return result;
                }
            }
            ++attributeLengthA;
        }
        
        for (var o in arguments[1]) {
            ++attributeLengthB;
        }
        
        //如果两个对象的属性数目不等，则两个对象也不等
        if (attributeLengthA != attributeLengthB)
            result = false;
        return result;
    }
    return arguments[0] == arguments[1];

}

var a = {Name:"YuanXP",Id:9,Go:{a:'1',b:'2'}};
var b = {Id:9,Name:"YuanXP",'Go':{a:'1',b:'2'}};

var c= equal(a, b);
console.log(c);