Extension implementation code collection of javascript array_javascript skills

Array.prototype.del = function(n)
{
if (n return this.slice(0,n).concat(this.slice(n 1,this. length));
}
//Array shuffle
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; i return -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
var strPos=arr.indexOf("me");