如果输入可以为空应该怎么写呢？

Question

  var regx = /^[1-9][0-9]{0,12}$/;
        var val = goodsWeigh;
        if(!regx.test(val)|| val!=""){
        alert("请输入至少为大于0的整数") 
        goodsWeigh.focus(); 
        }

Answer 1

 if(val!="" && !regx.test(val)){ 
        alert("请输入至少为大于0的整数") 
        goodsWeigh.focus(); 
        }

Answer 2

 var regx = /^[1-9][0-9]{0,12}$/; 
        var val = goodsWeigh; 
        if(!regx.test(val)){ 
        alert("请输入至少为大于0的整数") 
        goodsWeigh.focus(); 
        }