javascript - 从输入 ="number"获取 javascript 的值

Question

我已经尝试了这里和整个互联网上能找到的所有方法，但这行不通。

我只是想检查输入 type="number"以查看它是否与数据库中已有的数字匹配。现在我保持简单，因为我可以解决其余的问题。

这是我的代码:

输入:

 <input style="width: 50px; font-size: 17px;" type="number" min="1" autocomplete="off" id="days" name="days" value="1" onchange="daysChange(this.days)" required />

这是 JavaScript:

 function daysChange(days) {
     var day = document.getElementById("days");
     if (day == "3"){
         alert("You Already Have An Email Going Out That Day. Please Select Another Day.");
     }
 }

它没有获取天数的值。相反，如果我发出警报并让它输出值，这就是它所说的... [object HTMLInputElement]

Answer 1

你需要获得值(value):

function daysChange(days) {
 var day = document.getElementById("days");
 if (day.value == "3"){
 alert("You Already Have An Email Going Out That Day. Please Select Another Day.");
 }
 }