两个数组去重 js

//

var arr=[1,2,2,2,2,4,2,2,2,4,2,22,2,];

var arr1=[1,1,1,1,1,1,1,1,1,1,1,4,4,2,2,1];

function diff(arr,arr1){

var a=[];var b=[];var r;

for(var i=0;i<arr.length;i++){

var index=arr1.indexOf(arr[i]);

if(index!=-1){

var r=a[i];

for(var j=index;j<arr1.length;j++){

if(arr1[j]==arr[i]){

arr1.splice(j,1);

j=j-1;

}

}

for(var k=i+1;k<arr.length;k++){

if(arr[k]==arr[i]){

arr.splice(k,1);

k=k-1;

}

}

arr.splice(i,1);

i=i-1;

}

}

return arr.concat(arr1);

}

var result=diff(arr,arr1);

console.log(result);