JavaScript Remove duplicate Array entries method and principle

Arr[j]==i you seem to refer to the equality judgment when an array element is a number type ...
But often we may have to make equality judgments about different types of ... This is the practical application of the problem should be considered

Case of 1!=new number (1)
The situation of null==undefined

0== "0" situation and so on

So obviously simple = = and = = are not suitable.
A Equals method should be implemented independently to make equality judgments ... To set rules based on requirements

<script>
Array.prototype.del = function () {
var a = {}, c = [], L = this.length;
for (var i = 0; i < L; i++) {
var b = this[i];
var d = (typeof B) + B;
if (a[d] = = undefined) {
C.push (b);
A[D] = 1;
}
}
return C;
}
alert ([1, 1, 2, 3, 4, 5, 4, 3, 4, 4, 5, 5, 6, 7].del ());
</script>

Method Two

var arr = ["123", "123", "123", "123", "SFSDF", "123", "345", "123", "123", "345", "456", "567", "SDC"];
var str = [];
for (var i = 0,len = Arr.length;i < len;i++) {
! RegExp (Arr[i], "G"). Test (Str.join (",")) && (Str.push (arr[i));
}
alert (str);

Method Three

var x=[1,1,3,4,5,3];
var y=[];
var tarray=function (I,arr) {
var Yap=false;
for (Var j=0;j<arr.length;j++) {
if (arr[j]==i) {yap=true;break;};
}
if (!yap) Arr.push (i);
};
for (Var t=0;t<x.length;t++) {
Tarray (X[t],y);
}
alert (y.length);
Alert (y.tostring ());