获取2个数组中不同的元素

方法一

function (oldVal,newVal){
  var removeItemFieldName = '';
          for(let i in oldVal){
            var stra = oldVal[i];
            var count = 0;
            for(let j in newVal){
              var strb = newVal[j];
              if(stra == strb){
                count ++;
              }
            }
            if(count=== 0){ 
              removeItemFieldName=stra;
            }
          }
reture removeItemFieldName
}

方法二：

   getDiff(arr1, arr2) {
        return arr1.filter(key => !arr2.includes(key))
      },