Question

如何在另一个函数中使用一个函数的变量？我知道这已被问及并回答，但我无法将这些解决方案应用于我的特定代码。 Accessing variables from other functions without using global variables How to get a variable returned across multiple functions - Javascript/jQuery我正在https://github.com/icatcher-at/MP3RecorderJS使用名为MP3RecorderJS的库。在demo html页面上有以下代码：

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8">
<title>MP3 Recorder test</title>
</head>
<body id="index" onload="">

<script type="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript" src="mp3recorder.js"></script>
<script type="text/javascript">
var audio_context;

function __log(e, data) {
  log.innerHTML += "\n" + e + " " + (data || '');
}

$(function() {

  try {
    // webkit shim
    window.AudioContext = window.AudioContext || window.webkitAudioContext;
    navigator.getUserMedia = ( navigator.getUserMedia ||
                     navigator.webkitGetUserMedia ||
                     navigator.mozGetUserMedia ||
                     navigator.msGetUserMedia);
    window.URL = window.URL || window.webkitURL;

    var audio_context = new AudioContext;
    __log('Audio context set up.');
    __log('navigator.getUserMedia ' + (navigator.getUserMedia ? 'available.' : 'not  present!'));
  } catch (e) {
    alert('No web audio support in this browser!');
  }

  $('.recorder .start').on('click', function() {
    $this = $(this);
    $recorder = $this.parent();

    navigator.getUserMedia({audio: true}, function(stream) {
      var recorderObject = new MP3Recorder(audio_context, stream, { statusContainer:  $recorder.find('.status'), statusMethod: 'replace' });
      $recorder.data('recorderObject', recorderObject);

      recorderObject.start();
    }, function(e) { });
  });

  $('.recorder .stop').on('click', function() {
    $this = $(this);
    $recorder = $this.parent();

    recorderObject = $recorder.data('recorderObject');
    recorderObject.stop();

    recorderObject.exportMP3(function(base64_mp3_data) {
      var url = 'data:audio/mp3;base64,' + base64_mp3_data;
      var au  = document.createElement('audio');

      au.controls = true;
      au.src = url;
      $recorder.append(au);

      recorderObject.logStatus('');
    });

  });

});
</script>

<div class="recorder">
  Recorder 1
  <input type="button" class="start"  value="Record" />
  <input type="button" class="stop" value="Stop" />
  <pre class="status"></pre>
</div>

<div class="recorder">
  Recorder 2
  <input type="button" class="start"  value="Record" />
  <input type="button" class="stop" value="Stop" />
  <pre class="status"></pre>
</div>

<pre id="log"></pre>
</body>
</html>

在第56行，有变量 var url ='data：audio / mp3; base64，'+ base64_mp3_data;

如果我写一个新功能，如：

function testing() {
console.log(url)
}

如何将var url导入我的“测试”功能？为了使它工作，我创建了一个隐藏的div，使innerhtml等于var url，然后在我的第二个函数中引用该div。但这似乎非常hackish。

Answer 1

只需在函数外声明变量，如下所示：

var url;

然后，当你更新函数中的变量时，它的值将被简单地更新，并且它将可用于其他函数。

＆＃13;

var hello;

function changeVar() {

  hello = 'hello';

}

function displayVar() {

  alert(hello);

}

＆＃13;

<button onclick="changeVar()">Change the variable to "hello"</button>
<br/>
<button onclick="displayVar()">Display the variable's value</button>

＆＃13;

使用另一个函数的变量

1 个答案: