无法在materialize.css中使用javascript在单击时更改按钮颜色

Question

我是materialize.css的新手，实际上我想用javascript在点击时改变按钮的颜色。每次点击按钮时，都必须根据按钮内容产生不同的颜色。但是当我点击按钮时，它不会改变颜色。

  <div class=" buttons  row center-align">
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button0'  onclick ="answer('0')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option0"></span></button><br>  
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button1'  onclick ="answer('1')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option1"></span></button><br>
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button2'  onclick ="answer('2')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option2"></span></button><br>
<button class="btn col s12 m6 deep-purple darken-4 center-align" id='button3'  onclick ="answer('3')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option3"></span></button><br>
 </div>

javascript

 function answer(ans){
  var z = document.getElementById('option'+ans);
  var choice = z.innerHTML;
  var b = document.getElementById('button'+ans);
     if(choice == questions[x].answer){
       b.style.backgroundColor = '#008000'; 
       b.style.color = 'rgb(255, 255, 255)';}
     else{
       b.style.backgroundColor = '#700000';
       b.style.color = 'rgb(255, 255, 255)';}

Answer 1

html

<div class=" buttons  row center-align">
<button class="button col s12 m6  center-align" id='button0'  onclick ="answer('0')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option0"></span></button><br>  
<button class="button col s12 m6  center-align" id='button1'  onclick ="answer('1')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option1"></span></button><br>
<button class="button col s12 m6  center-align" id='button2'  onclick ="answer('2')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option2"></span></button><br>
<button class="button col s12 m6  center-align" id='button3'  onclick ="answer('3')" style ="display:none"><span class=" flow-text white-text text-darken-2" id="option3"></span></button><br>

​

只需删除materializecss按钮类'btn‘并替换为任何名称，我对button执行了操作，并删除了button标记中的materializecss颜色类，所以最后每个按钮都属于class：

 'button col s12 m6  center-align' 

并在此html文件的自创建css文件中(main.css)

.button.col.s12.m6.center-align{
   background-color: #311b92;
padding: 10px 20px 10px;
border-radius: 50px;
font-size: 2em;}

现在，当我们应用上述问题中提到的javascript方法时，按钮的颜色将在单击时发生变化