提交时如何更改文本答案

【问题标题】：How do i change the text when i'm submitting提交时如何更改文本
【发布时间】：2020-09-20 18:05:49
【问题描述】：

提交时，我无法将“输入您的年龄”中的文本更改为“您的年龄”。有没有办法在我提交 DOB 时将“输入您的年龄”更改为“您的年龄是：X”？

function myFunction() {
  var dobString = document.getElementById("birth_date").value;
  var calculatedValue = calculate_age(dobString);
}

function calculate_age(dobString) {
  var diff_ms = Date.now() - Date.parse(dobString);
  var yearString = "";
  var yearValue = Math.floor(diff_ms / 31536000000);
  console.log("Years ", yearValue);

  if (yearValue > 1) 
    yearString = " years";
  else
    yearString = " year";

  if (yearValue > 0)
    var calculatedValue = yearValue + yearString + " ";
  else if (yearValue == 0)
    var calculatedValue = monthValue + monthString + " ";

  document.getElementById("age").innerHTML = "Your Age is : " + calculatedValue;
}

<form>
  Birthday: <input type="date" name="bday" id="birth_date">
  <br><br>
</form>

<button onclick="myFunction()">view</button><br>
<h2>Enter your age</h2>
<p id="age"></p>

【问题讨论】：

标签： javascript html jquery ajax dom

【解决方案1】：

将模板更新为

 <h2 id="age">Enter your age</h2>

并将脚本更新为这样

document.getElementById("age").textContent = "Your Age is : " + calculatedValue;

【讨论】：

【解决方案2】：

很简单，把id="age"放在<h2>上

function myFunction() {
  var dobString = document.getElementById("birth_date").value;
  var calculatedValue = calculate_age(dobString);
}

function calculate_age(dobString) {
  var diff_ms = Date.now() - Date.parse(dobString);
  var yearString = "";
  var yearValue = Math.floor(diff_ms / 31536000000);
  console.log("Years ", yearValue);

  if (yearValue > 1) 
    yearString = " years";
  else
    yearString = " year";

  if (yearValue > 0)
    var calculatedValue = yearValue + yearString + " ";
  else if (yearValue == 0)
    var calculatedValue = monthValue + monthString + " ";

  document.getElementById("age").innerHTML = "Your Age is : " + calculatedValue;
}

<form>
  Birthday: <input type="date" name="bday" id="birth_date">
  <br><br>
</form>

<button onclick="myFunction()">view</button><br>
<h2 id="age">Enter your age</h2>

【讨论】：

但是段落标签的 id 是年龄。只是移动它不会解决问题

【解决方案3】：

您需要稍微不同地计算年龄。也许是这样的：

function calculate_age(dobString) {
    var birthday = new Date(dobString),  //Year, month, day.
    today = new Date(),
    one_year = 1000*60*60*24*365;
    let yearValue = Math.floor( (today.getTime() - birthday.getTime() ) / one_year);

    let yearString = 'year'
    if (yearValue > 1){ yearString += "s" };

    document.getElementById("age").innerHTML = `Your Age is : ${yearValue} ${yearString}`;
}

我创建了一个小提琴供您查看它的实际效果：

https://jsfiddle.net/cdrsfo82/

【讨论】：