Array Functionality

An old script I recently found reasons to bring to life again...

/*
* Array Functionality
* script: array.js
* for: browsers not implementing the full array functionality of ECMA262-3
* by: liorean <http://liorean.web-graphics.com/>
* thanks to: beetle
*/

if(typeof Array.prototype.copy=='undefined')
Array.prototype.copy=function(a){
var
i=0,
b=[];
for(i;i<this.length;i++)
b[i]=(typeof this[i].copy!='undefined')?
this[i].copy():
this[i];
return b
};

if(typeof Array.prototype.concat=='undefined')
Array.prototype.concat=function(a){
var
i=0,
b=this.copy();
for(i;i<a.length;i++)
b[b.length]=a[i];
return b
};

if(typeof Array.prototype.pop=='undefined')
Array.prototype.pop=function(){
var
b=this[this.length-1];
this.length--;
return b
};

if(typeof Array.prototype.push=='undefined')
Array.prototype.push=function(){
var
i=0,
b=this.length,
a=arguments;
for(i;i<a.length;i++)
this[b+i]=a[i];
return this.length
};

if(typeof Array.prototype.shift=='undefined')
Array.prototype.shift=function(){
var
i=0,
b=this[0];
for(i;i<this.length-1;i++)
this[i]=this[i+1];
this.length--;
return b
};

if(typeof Array.prototype.slice=='undefined')
Array.prototype.slice=function(a,c){
var
i=0,
b,
d=[];
if(!c)
c=this.length;
if(c<0)
c=this.length+c;
if(a<0)
a=this.length-a;
if(c<a){
b=a;
a=c;
c=b
}
for(i;i<c-a;i++)
d[i]=this[a+i];
return d
};

if(typeof Array.prototype.splice=='undefined')
Array.prototype.splice=function(a,c){
var
i=0,
e=arguments,
d=this.copy(),
f=a;
if(!c)
c=this.length-a;
for(i;i<e.length-2;i++)
this[a+i]=e[i+2];
for(a;a<this.length-c;a++)
this[a+e.length-2]=d[a-c];
this.length-=c-e.length+2;
return d.slice(f,f+c)
};

if(typeof Array.prototype.unshift=='undefined')
Array.prototype.unshift=function(a){
var
b;
this.reverse();
b=this.push(a);
this.reverse();
return b
};