kishan patel kishan patel - 6 months ago 40
Javascript Question

How to display javascript variables in a html page without document.write

I am trying to display some javascript variable on my html page.

I was first using

document.write()
but it use to overwrite the current page when the function was called.

After searching around, the general consensus was that
document.write()
isn't liked very much. What are the other options?

I found a page suggesting using
.innerHTML
but that was written in 2005.

A js fiddle illustrating my problem http://jsfiddle.net/xHk5g/

Answer

Element.innerHTML is pretty much the way to go. Here are a few ways to use it:

HTML

<div class="results"></div>

JavaScript

// 'Modern' browsers (IE8+, use CSS-style selectors)
document.querySelector('.results').innerHTML = 'Hello World!';

// Using the jQuery library
$('.results').html('Hello World!');

If you just want to update a portion of a <div> I usually just add an empty element with a class like value or one I want to replace the contents of to the main <div>. e.g.

<div class="content">Hello <span class='value'></span></div>

Then I'd use some code like this:

// 'Modern' browsers (IE8+, use CSS-style selectors)
document.querySelector('.content .value').innerHTML = 'World!';

// Using the jQuery library
$(".content .value").html("World!");

Then the HTML/DOM would now contain:

<div class="content">Hello <span class='value'>World!</span></div>

Full example. Click run snippet to try it out.

// Plain Javascript Example
var $jsName = document.querySelector('.name');
var $jsValue = document.querySelector('.jsValue');

$jsName.addEventListener('input', function(event){
  $jsValue.innerHTML = $jsName.value;
}, false);


// JQuery example
var $jqName = $('.name');
var $jqValue = $('.jqValue');

$jqName.on('input', function(event){
  $jqValue.html($jqName.val());
});
html {
  font-family: sans-serif;
  font-size: 16px;
}

h1 {
  margin: 1em 0 0.25em 0;
}

input[type=text] {
  padding: 0.5em;
}

.jsValue, .jqValue {
  color: red;
}
<!DOCTYPE html>
<html>
<head>
<script src="https://code.jquery.com/jquery-1.11.3.js"></script>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Setting HTML content example</title>
</head>
<body>
  <!-- This <input> field is where I'm getting the name from -->
  <label>Enter your name: <input class="name" type="text" value="World"/></label>
  
  <!-- Plain Javascript Example -->
  <h1>Plain Javascript Example</h1>Hello <span class="jsValue">World</span>
  
  <!-- jQuery Example -->
  <h1>jQuery Example</h1>Hello <span class="jqValue">World</span>
</body>
</html>

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