Array.prototype.unique1 = function(){
var res = [this[0]];
for(var i = 1; i < this.length; i++){
var repeat = false;
for(var j = 0; j < res.length; j++){
if(this[i] == res[j]){
repeat = true;
break;
}
}
if(!repeat){
res.push(this[i]);
}
}
return res;
}
var array1=[1,2,3,4,5,6,7,7,8,]
array1.unique1()