使用javascript，如何在HTML页面上的任何输入元素之前添加$ sign

Question

使用javascript，如何在HTML页面上的任何输入字段之前添加“$”符号？

Answer 1

You can get all input field on page using document.getElementsByTagName('input') and then use Node.insertBefore() function inside a loop to insert dollar sign $ before every one of them :

 var inputs = document.getElementsByTagName('input'); for ( var i=0 ; i < inputs.length ; i++){ var text = document.createTextNode('$'); inputs[i].parentNode.insertBefore(text, inputs[i]); } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input type="text" /><br/> <input type="text" /><br/> <input type="text" /><br/> <input type="text" /><br/> <input type="text" /> 

Hope this helps.

Answer 2

Alternatively you could use pure CSS to do so, by using the :before or :after pseudo elements and wrapping your input containers in div 's

 .inputContainer:before, .inputContainer::before { content: '$'; } 

 <div class="inputContainer"> <input type="text"> </div>