codewars算法题-Array.diff

算法要求:

Your goal in this kata is to implement an difference function, which subtracts one list from another.

It should remove all values from list a, which are present in list b.

c方法，双重循环:

function array_diff(a, b) {
var bLength = b.length;
for(var i = 0; i<bLength; i++){
for(var j = 0; j<a.length; ){
if(b[i]==a[j]){
a.splice(j,1);
}else {
j++
}
}
}
return a;
}

js方法 ,调用自带的一个indexOf:

function array_diff(a, b) {
for(var i = 0;i<a.length;){
if(b.indexOf(a[i])>-1){
a.splice(i,1);
}else{
i++;
}
}
return a;
}

不知道C是怎么删除数组中某一元素的？？？？