indexOf封装,查找数组里面是否有这个值(function hasVal(){})?

 //查找数组里面是否有这个值
    var ary=[1,2,3,4,null]
    function hasVal(ary,val){
        if(ary.indexOf(val)>-1){
          return true;
        }else{
          return false;
        }
    }
    console.log(hasVal(ary,3));//ture
    console.log(hasVal(ary,10));//false