Extended example code of JS array_javascript skills

Array.prototype.del = function(n)
{
if (nreturn this.slice(0,n).concat(this.slice (n 1,this.length));
}
//Array shuffling
Array.prototype.random = function()
{
var nr=[], me=this , t;
while(me.length>0)
{
nr[nr.length] = me[t = Math.floor(Math.random() * me.length)];
me = me.del(t);
}
return nr;
}
//Number array sorting
Array.prototype.sortNum = function(f)
{
if (!f) f=0;
if (f==1) return this.sort(function(a,b){return b-a;});
return this.sort(function(a ,b){return a-b;});
}
// Get the maximum item of the numeric array
Array.prototype.getMax = function()
{
return this.sortNum(1 )[0];
}
// Get the minimum item of the numeric array
Array.prototype.getMin = function()
{
return this.sortNum(0)[0];
}
//The position where the specified element value first appears in the array
Array.prototype.indexOf = function(o)
{
for (var i=0; ireturn -1;
}
// Remove duplicate items in the array
Array.prototype.removeRepeat=function ()
{
this.sort();
var rs = [];
var cr = false;
for (var i=0; i{
if (!cr) cr = this[i];
else if (cr==this[i]) rs[rs.length] = i;
else cr = this[ i];
}
var re = this;
for (var i=rs.length-1; i>=0; i--) re = re.del(rs[i]);
return re;
}

Example:
var arr=["ni","wo","ta"];
Delete "wo" in the array
var newArr=arr.del(1);
Returns the position where "me" first appears in the array, if not, returns -1