JS 数组去重

<script>
Array.prototype.numberRepeat=function(){
var numberContent=[this[0]];
for(var i=1;i<this.length;i++){
var repeat=false;
for(var j=0;j<numberContent.length;j++){
if(this[i]==numberContent[j]){
repeat=true;
break;
}
}
if(!repeat){
numberContent.push(this[i]);
}

}
return  numberContent;
}
var arr=[2,3,4,5,6,7,8,9,0,1,3,5,6];
console.log(arr.numberRepeat());

</script>