我如何检查用户的输入值是否具有特定数字？

Question

因为我是新手，所以我想检查一下用户输入的值是否等于一个特定的数字。

我需要检查用户输入的值是否低于 10。我做了下面的代码：

<form>
  <label for="value">Value</label>
  <input type="number" id="quantity" name="number"><br><br>
  <input type="button" value="Click me" onclick="myFunction()">
</form>
<p id="answer">answer here</p>
<script>

function myFunction() {
   var x= document.getElementbyId("quantity").value;
    if (x<10){
     document.getElementbyId("answer").innerHTML="The value is below 10"
}   else {
    document.getElementbyId("answer").innerHTML="The value is equal to or over 10";
  }
}
</script>

Answer 1

您的代码运行正常，只需将 getElementbyId 替换为 getElementById。下面的代码片段正是您的代码，替换了 getElementbyId.

<form>
  <label for="value">Value</label>
  <input type="number" id="quantity" name="number"><br><br>
  <input type="button" value="Click me" onclick="myFunction()">
</form>
<p id="answer">answer here</p>
<script>
  function myFunction() {
    var x = document.getElementById("quantity").value;
    if (x < 10) {
      document.getElementById("answer").innerHTML = "The value is below 10"
    } else {
      document.getElementById("answer").innerHTML = "The value is equal to or over 10";
    }
  }
</script>

我如何检查用户的输入值是否具有特定数字？

How can i check if the user's input value has a specific number?

html

forms

if-statement

input