如何用另一个变量定义一个变量? [英] How can I define a variable with another variable?

问题描述

我想用 JavaScript 保存音频文件列表.

I want to save a list of audio files in javascript.

function save() {
   for(i=1; i<5; i++){
      s=document.getElementById("s"+i);
   };
}

音频文件是这样的:

<audio id="s1"><source src="Sounds/s1.mp3"type="audio/mpeg"></audio>
<audio id="s2"><source src="Sounds/s2.mp3"type="audio/mpeg"></audio>
<audio id="s3"><source src="Sounds/s3.mp3"type="audio/mpeg"></audio>
<audio id="s4"><source src="Sounds/s4.mp3"type="audio/mpeg"></audio>

但直到 s30.

如何使变量也发生变化，以便将这些音频文件另存为不同的变量?

How can I make variable s also change so I can save these audio files as different variables?

推荐答案

您可以使用对象来存储像 hashmap/properties 或使用数组来执行此操作，请参阅以下示例:

You can use a object to store like a hashmap/properties or use a array to do this, see the examples bellow:

对象:

function save() {
   var audios = {};
   for(i=1; i<5; i++){
      var id = "s"+i;
      audios[id] = document.getElementById(id);
   };
   return audios;
}


var audios = save();

console.log(audios["s2"]);
console.log(audios["s3"]);

<audio id="s1"><source src="Sounds/s1.mp3"type="audio/mpeg"></audio>
<audio id="s2"><source src="Sounds/s2.mp3"type="audio/mpeg"></audio>
<audio id="s3"><source src="Sounds/s3.mp3"type="audio/mpeg"></audio>
<audio id="s4"><source src="Sounds/s4.mp3"type="audio/mpeg"></audio>

数组:

function save() {
   var audios = [];
   for(i=1; i<5; i++){
      var id = "s"+i;
      audios.push(document.getElementById(id));
   };
   return audios;
}


var audios = save();

console.log(audios[1]);
console.log(audios[2]);

<audio id="s1"><source src="Sounds/s1.mp3"type="audio/mpeg"></audio>
<audio id="s2"><source src="Sounds/s2.mp3"type="audio/mpeg"></audio>
<audio id="s3"><source src="Sounds/s3.mp3"type="audio/mpeg"></audio>
<audio id="s4"><source src="Sounds/s4.mp3"type="audio/mpeg"></audio>

一次选择所有:

var audio = document.querySelectorAll('audio');

console.log(audio[0]);
console.log(audio[1]);
console.log(audio[2]);
console.log(audio[3]);

<audio id="s1"><source src="Sounds/s1.mp3"type="audio/mpeg"></audio>
<audio id="s2"><source src="Sounds/s2.mp3"type="audio/mpeg"></audio>
<audio id="s3"><source src="Sounds/s3.mp3"type="audio/mpeg"></audio>
<audio id="s4"><source src="Sounds/s4.mp3"type="audio/mpeg"></audio>

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