Question

试图通过名为“另类”的音乐流派来更改ID为“ musiclist”的列表中的第三项。我已经尝试了document.getElementbyID，但是它不起作用。

<!DOCTYPE html>
    <html lang="en">
    <head>
    <meta charset="utf-8">
    <script>
      function thirdItem() {
        document.getElementbyId("thirdItem").innerHTML("Alternative");}
        </script> 

    <title> Music Genres </title>
    </head>
    <body>
    <div id="main">
    <h1> Favorite genre of music </h1>
    <p>My favorite type of music include:</p>
    <!--A list of genres of music-->
    <ol id="musiclist">
    <li id="firstItem"> Rock </li>
    <li id="SecondItem"> Hip hop</li>
    <li id="thirdItem"> Country </li>

    </ol>
    </div>
    </body>
    </html>

Answer 1

因此，您已经创建了一个方法，该方法在调用时将更改该元素的log4j.rootCategory=INFO, stdout, file log4j.category.audit=TRACE,audit log4j.category.audit.additivity.audit=false log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d{DATE} %5p %c{1}:%L - %m%n log4j.appender.file=org.apache.log4j.DailyRollingFileAppender log4j.appender.file.File=${catalina.home}/logs/customer-backend.log log4j.appender.file.datePattern='.'yyyy-MM-dd log4j.appender.file.Append=true log4j.appender.file.Encoding=UTF-8 log4j.appender.file.layout=org.apache.log4j.PatternLayout log4j.appender.file.layout.ConversionPattern= %d{dd MMM yy HH:mm:ss} %1p %t %c{2}:%L - %m%n log4j.appender.audit=org.apache.log4j.DailyRollingFileAppender log4j.appender.audit.File=${catalina.home}/logs/spa-web-audit.log log4j.appender.audit.Append=true log4j.appender.audit.Encoding=UTF-8 log4j.appender.audit.layout=org.apache.log4j.PatternLayout log4j.appender.audit.layout.ConversionPattern=%d{ABSOLUTE} %5p %t %c{2}:%L - %m%n log4j.logger.org.springframework.beans.factory=INFO log4j.logger.org.springframework=INFO log4j.logger.org.springframework.security=INFO log4j.logger.audit=TRACE log4j.logger.com.clicksmob.backoffice.customer.svc.periodic=TRACE log4j.logger.com.clicksmob.backoffice.customer.svc.periodic.actions.offers.media=WARN log4j.logger.org.hibernate=INFO，但是存在一些问题

您永远不会调用该方法
函数名称区分大小写，因此应为innerHTML而不是getElementById
getElementbyId是属性而不是方法，因此请为其分配一个值innerHTML

.innerHTML = '...';

Answer 2

script应该放在body的底部
您最好在编码前检出doc。

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="utf-8">


  <title> Music Genres </title>
</head>

<body>
  <div id="main">
    <h1> Favorite genre of music </h1>
    <p>My favorite type of music include:</p>
    <!--A list of genres of music-->
    <ol id="musiclist">
      <li id="firstItem"> Rock </li>
      <li id="SecondItem"> Hip hop</li>
      <li id="thirdItem"> Country </li>

    </ol>
  </div>
  <script>
    function thirdItem() {
      document.getElementById("thirdItem").innerHTML="Alternative";
    }
    thirdItem()
  </script>
</body>

</html>

Answer 3

将脚本移动到文件或新文件的末尾
为getElementById的B加上大写字母
您可以使用=

<!DOCTYPE html>
    <html lang="en">
    <head>
    <meta charset="utf-8">

    <title> Music Genres </title>
    </head>
    <body>
    <div id="main">
    <h1> Favorite genre of music </h1>
    <p>My favorite type of music include:</p>
    <!--A list of genres of music-->
    <ol id="musiclist">
    <li id="firstItem"> Rock </li>
    <li id="SecondItem"> Hip hop</li>
    <li id="thirdItem"> Country </li>

    </ol>
    </div>
    </body>
    </html>
        <script>
    function thirdItem(){document.getElementById("thirdItem").innerHTML = "Alternative"}
        thirdItem();
    </script>

Answer 4

您需要更改代码：

 function thirdItem() {
  document.getElementById("thirdItem").innerHTML = "Alternative";
}

对此：

document.getElementById("thirdItem").innerHTML = "Alternative";

此外，您还需要将脚本块移动到文件底部。

原因是，您声明了函数，但从不调用它。

Answer 5

您必须在正文结束前添加JavaScript代码。

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">


<title> Music Genres </title>
</head>
<body>
<div id="main">
<h1> Favorite genre of music </h1>
<p>My favorite type of music include:</p>
<!--A list of genres of music-->
<ol id="musiclist">
<li id="firstItem"> Rock </li>
<li id="SecondItem"> Hip hop</li>
<li id="thirdItem"> Country </li>

</ol>
</div>
<script>
  function thirdItem() {
    document.getElementbyId("thirdItem").innerHTML = "Alternative";}
    </script> 
</body>
</html>

使用JavaScript更改元素ID？

5 个答案: