JavaScript深度比较数组与对象相等性的实现方案

      arrayEquals(array1, array2) {
        // if array1 or array2 is a falsy value, return
        if (!array1 || !array2)
          return false;
        // compare lengths - can save a lot of time
        if (array1.length != array2.length)
          return false;
        for (var i = 0, l = array1.length; i < l; i++) {
          // Check if we have nested arrays
          if (array1[i] instanceof Array && array2[i] instanceof Array) {
            // recurse into the nested arrays
            if (!this.arrayEquals(array1[i], array2[i]))
              return false;
          } else if (array1[i] instanceof Object && array2[i] instanceof Object) {
            // 比较含有的对象是否相等
            if (!this.objectEquals(array1[i], array2[i]))
              return false;
          } else if (array1[i] != array[i]) {
            // Warning - two different object instances will never be equal: {x:20} != {x:20}
            return false;
          }
        }
        return true;
      },
      objectEquals(object1, object2) {
        //For the first loop, we only check for types
        for (let propName in object1) {
          //Check for inherited methods and properties - like .equals itself
          //https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty
          //Return false if the return value is different
          if (object1.hasOwnProperty(propName) != object2.hasOwnProperty(propName)) {
            return false;
          }
          //Check instance type
          else if (typeof object1[propName] != typeof object2[propName]) {
            //Different types => not equal
            return false;
          }
        }
        //Now a deeper check using other objects property names
        for (let propName in object2) {
          //We must check instances anyway, there may be a property that only exists in object2
          //I wonder, if remembering the checked values from the first loop would be faster or not
          if (object1.hasOwnProperty(propName) != object2.hasOwnProperty(propName)) {
            return false;
          } else if (typeof object1[propName] != typeof object2[propName]) {
            return false;
          }
          //If the property is inherited, do not check any more (it must be equa if both objects inherit it)
          if (!object1.hasOwnProperty(propName))
            continue;

          //Now the detail check and recursion

          //This returns the script back to the array comparing
          /**REQUIRES Array.equals**/
          if (object1[propName] instanceof Array && object2[propName] instanceof Array) {
            // recurse into the nested arrays
            if (!this.arrayEquals(object1[propName], object2[propName]))
              return false;
          } else if (object1[propName] instanceof Object && object2[propName] instanceof Object) {
            // recurse into another objects
            if (!this.objectEquals(object1[propName], object2[propName]))
              return false;
          }
          //Normal value comparison for strings and numbers
          else if (object1[propName] != object2[propName]) {
            return false;
          }
        }
        //If everything passed, let's say YES
        return true;
      }

  var obj1={0:'a',1:'b',2:'c'}
   var obj2={0:'a',1:'b',2:'c'}
   console.log(obj1==obj2)
   console.log(obj1===obj2)

//判断两个对象是否相同（包含绝对相等和他们是否有相同的形状）
 function looseEqual (a, b) {
    if (a === b) { //如果是绝对相等就直接返回true
    	return true ;
    }
    //如果不是绝对相等就哦按的他们是否有相同的形状
    var isObjectA = isObject(a);
    var isObjectB = isObject(b);
    if (isObjectA && isObjectB) {//两个均是对象
      try {
        var isArrayA = Array.isArray(a);
        var isArrayB = Array.isArray(b);
        if (isArrayA && isArrayB) {//如果都是数组
        	if(a.length === b.length){//如果长度相等
        	    return a.every(function (e, i) {//用every和递归来比对a数组和b数组的每个元素，并返回
	           	  return looseEqual(e, b[i])
	            })
        	}
        	//长度都不等直接返回false
        	return  false;
        } else if (a instanceof Date && b instanceof Date) {//如果是Date 则直接getTime 比较
           return a.getTime() === b.getTime()
        } else if (!isArrayA && !isArrayB) {//对象的比较
          //拿到两个对象的key
          var keysA = Object.keys(a);
          var keysB = Object.keys(b);
          if(keysA.length === keysB.length){//如果keys相等
          	  return keysA.every(function (key) {//用every和递归来比对a对象和b对象的每个元素值，并返回
	            return looseEqual(a[key], b[key]);
	          })
          }
          //长度都不等直接返回false
          return false;
        } else {
          return false
        }
      } catch (e) {
        return false
      }
    } else if (!isObjectA && !isObjectB) {//如果都不是对象则按String来处理
        return String(a) === String(b)
    } else {
        return false
    }
  }
  
  function isObject (obj) {
    return obj !== null && typeof obj === 'object'
  }

 //字符
   var str1="abc";
   var str2="abc";
   console.log(looseEqual(str1,str2))
   
   //数字
   var num1=12222;
   var num2=12222;
   console.log(looseEqual(num1,num2))
   
   //对象
   var obj1={0:'a',1:'b',2:'c'}
   var obj2={0:'a',1:'b',2:'c'}
   console.log(looseEqual(obj1,obj2))
   
   //对象嵌套数组
   var obj1={0:'a',1:'b',2:[1,2,3]}
   var obj2={0:'a',1:'b',2:[1,2,3]}
   console.log(looseEqual(obj1,obj2))
   
  //类数组
   var a={0:'a',1:'b',2:'c','length':3}
   var b={0:'a',1:'b',2:'c','length':3}
   console.log(looseEqual(a,b))
   
   //数组
   var list=[1,2,3,4]
   var list1=[1,2,3,4]
   console.log(looseEqual(list,list1))
   
   //数组嵌套
    list=[1,2,3,[6,7]]
    list1=[1,2,3,[6,7]]
   console.log(looseEqual(list,list1))
   
    //数组嵌套对象
    list=[1,2,3,{a:'1',b:'7'}]
    list1=[1,2,3,{a:'1',b:'7'}]
   console.log(looseEqual(list,list1))
   
   var d1 = new Date();
   var d2 = new Date();
   console.log(looseEqual(d1,d2))
   
   var d3 = new Date();
   var d4 ;
   //使用延时来赋值d4
   setTimeout(function(){
   		d4 = new Date();
   		console.log(looseEqual(d3,d4))
   },1);