js Reconstruct Array's sort sorting method_javascript skills

This sorting is a pairwise comparison.
Take this array and sort it in descending order var a = [3, 1, 5, 6, 4, 2];
First round of comparison: compare the first value with other elements of this array
3 to 1
3 to 5 //5 is larger, so the exchange results in a = [5, 1, 3, 6, 4, 2];
5 to 6 //The exchange results in a = [6 , 1, 3, 5, 4, 2];
6 to 4
6 to 2
The final result of the first round a = [6, 1, 3, 5, 4, 2];
Second round of comparison: Compare the second value with the elements after this value
1 to 3 //Exchange to get a = [6, 3, 1, 5, 4, 2];
3 to 5 //Exchange a = [6, 5, 1, 3, 4, 2];
5 to 4
5 to 2
The final result of the second round is a = [6, 5, 1, 3, 4, 2];
Exchange in this way
The final result of the third round a = [6, 5, 4, 1, 3, 2];
The final result of the fourth round a = [ 6, 5, 4, 3, 1, 2];
The final result of the fifth round a = [6, 5, 4, 3, 2, 1];
The following is the reconstruction method:

Copy code The code is as follows:

Array.prototype.fst = function(fn){
var fn = fn || function(a, b){ return a > b;};
for(var i=0; ifor(var j=i; j< ;this.length; j ){
if(fn(this[i], this[j]) > 0){
var t = this[i];
this[i] = this [j];
this[j] = t;
}
}
}
return this;
};

View actual demo

<meta charset="utf-8"> <title>index</title> <meta name="auther" content="F7"> Look at the source code, the source code is clearer!
[Ctrl A select all Note:

If you need to introduce external Js, you need to refresh to execute <script> Array.prototype.fst = function(fn){ var fn = fn || function(a, b){ return a > b;}; for(var i=0; i<this.length; i++){ for(var j=i; j<this.length; j++){ if(fn(this[i], this[j]) > 0){ var t = this[i]; this[i] = this[j]; this[j] = t; } } } return this; }; </script>]<script> var a = [3, 1, 5, 6, 4, 2]; //a.fst(); //alert(a.fst().join()); alert(a.fst(function(a, b){ return a < b}).join()); //alert(a.fst(function(a, b){ return a - b}).join()); //alert(a.sort(function(){ return 1})); //alert(a.fst(function(){ return 1})); </script>