Add a Space (" ") After an Element Using :After

h2 {  text-decoration: underline;}h2.space::after {  content: " ";  white-space: pre;}

<h2>I don't have space:</h2><h2 class="space">I have space:</h2>

Add space between two words in a ::After Pseudo element CSS

You can use \00a0 instead of spaces in the content property. They don't get collapsed into a single space.

.c1::after{
    content: "SUB TITLE\00a0\00a0THE EXAMPLE";
}

Best practice when adding whitespace in JSX

Because   causes you to have non-breaking spaces, you should only use it where necessary. In most cases, this will have unintended side effects.

Older versions of React, I believe all those before v14, would automatically insert <span> </span> when you had a newline inside of a tag.

While they no longer do this, that's a safe way to handle this in your own code. Unless you have styling that specifically targets span (bad practice in general), then this is the safest route.

Per your example, you can put them on a single line together as it's pretty short. In longer-line scenarios, this is how you should probably do it:

  <div className="top-element-formatting">
    Hello <span className="second-word-formatting">World!</span>
    <span> </span>
    So much more text in this box that it really needs to be on another line.
  </div>

This method is also safe against auto-trimming text editors.

The other method is using {' '} which doesn't insert random HTML tags. This could be more useful when styling, highlighting elements, and removes clutter from the DOM. If you don't need backwards compatibility with React v14 or earlier, this should be your preferred method.

  <div className="top-element-formatting">
    Hello <span className="second-word-formatting">World!</span>
    {' '}
    So much more text in this box that it really needs to be on another line.
  </div>

How to append a space after an element

Since you asked for some visual whitespace - the simplest and most flexible way is applying it through CSS, not using a space character:

img {
    margin-right: 5px;
}

If you want to only apply it to the specific element you create, you can use JavaScript to apply the CSS: http://jsfiddle.net/aRcPE/.

image.style.marginRight = "5px"; // "foo-bar" becomes "fooBar" since
                                 // the hyphen is not allowed in this notation

How to insert space every 4 characters for IBAN registering?

The existing answers are relatively long, and they look like over-kill. Plus they don't work completely (for instance, one issue is that you can't edit previous characters).

For those interested, according to Wikipedia:

Permitted IBAN characters are the digits 0 to 9 and the 26 upper-case Latin alphabetic characters A to Z.

Here is a relatively short version that is similar to the existing answers:

document.getElementById('iban').addEventListener('input', function (e) {  e.target.value = e.target.value.replace(/[^\dA-Z]/g, '').replace(/(.{4})/g, '$1 ').trim();});

<label for="iban">iban</label><input id="iban" type="text" name="iban" />

$("#mySelector").append(" "); // or with & nbsp;

div.innerHTML += ' ';

div.innerHTML += ' ';

p:before { content: "\00a0 "; }

<p style="margin: 0;">Text</p>

label[data-valid="error"] input{
  padding-top:15px;
}