Determine whether reference type objects such as Object, Array, and Function are equal in js_javascript skills

During iteration, we also need to note that the element in the object or array may be an arbitrary value - in addition to primitive type values, objects, arrray, this value may also be a method, a DOM object or a window object, possibly You have noticed that some reference types cannot be iterated and require branch judgment. The code is as follows:

Copy code The code is as follows :

function compare(a,b){
var
pt = /undefined|number|string|boolean/,
fn = /^(functions*)(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)) ; //For convenience, it is assumed here that 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'); //The way the function is declared in hard coding will affect the result of toString, so use regular formatting
};
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])); //false
console. log(compare(document.getElementsByTagName("a")[0],document.getElementsByTagName("a")[0])); //true