js 数组去重

var contarray = [1,2,1,2,525,72,4,4,1,25];
deweight(contarray);

function deweight(arr){
var liall = [],contrast = true;
for(var i=0; i<arr.length; i++){

for(var j=0; j < i; j++){

if(arr[i] == arr[j]){
contrast = false;
break;
}else{
contrast = true;
}
}
if(contrast){
liall[i] = arr[i];
}
}
return liall;
}