//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复制代码