What Is HTML's <A></A> Tag Default Display Type

What is HTML's <a></a> tag default display type?

It is always display: inline by default. Horizontal margins, and padding on all sides should work without having to change its display property.

This remains true even in HTML5. If you are applying styles to an <a> element that contains flow elements or any other elements that are represented in CSS as display: block, you should set the <a> itself to a proper block container type such as block or inline-block for its layout to work as intended.

What is the HTML buttons' default display mode?

A button is by default an inline-block, so multiple buttons without a line break or some will be displayed next to each other:

<button>button 1</button><button>button 2</button>

What are the default CSS styling of heading tags? (H1, h2, h3, h4, h5)

The answer is no, however you might hack the styles. Most browsers will try to use these styles

(Taken from: w3schools)

h1 { 
    display: block;
    font-size: 2em;
    margin-top: 0.67em;
    margin-bottom: 0.67em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}
h2 {
    display: block;
    font-size: 1.5em;
    margin-top: 0.83em;
    margin-bottom: 0.83em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}
h3 { 
    display: block;
    font-size: 1.17em;
    margin-top: 1em;
    margin-bottom: 1em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}
h4 { 
    display: block;
    margin-top: 1.33em;
    margin-bottom: 1.33em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}
h5 { 
    display: block;
    font-size: .83em;
    margin-top: 1.67em;
    margin-bottom: 1.67em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}
h6 { 
    display: block;
    font-size: .67em;
    margin-top: 2.33em;
    margin-bottom: 2.33em;
    margin-left: 0;
    margin-right: 0;
    font-weight: bold;
}

is the <head> tag a regular tag that is not displayed by default

In terms of pure display - yes {display:none;} will hide your element.

However HTML <head> has a distinct meaning in HTML as a container for the head elements, whereas <cheese> does not share this.

Browsers know it's not to be displayed and search engine crawlers understand the special meaning of the <head> tag.

Where to find the default `display` style attribute for a HTML tag?

Default display style attribute of <img> tag is inline and its mentioned in this MDN document for inline elements.

The following elements are "inline":

b, big, i, small, tt

abbr, acronym, cite, code, dfn, em, kbd, strong, samp, var

a, bdo, br, img, map, object, q, script, span, sub, sup

button, input, label, select, textarea

Hope it helps!

HTML anchor tag takes entire line

Regular anchor Tags are inline elements. You have to check if in your CSS, you already assign anchors globally to a block element. a { display: block;}

For fast fix:
Wrap your code anchor line (Breadcrumbs) in a container and assign with a unique id or class Name. Then you can assign only for this line the anchors to a inline element.

a {
 display: block;
}
.anchor-regular a {
  display: inline;
}

<a href="">test block </a> <a href="">test block</a>
<div class="anchor-regular">
<a href="">First Link</a> / <a href="">Second Link</a> / <a href="">Third Link</a>
</div>

Is there an opposite to display:none?

display: none doesn’t have a literal opposite like visibility:hidden does.

The visibility property decides whether an element is visible or not. It therefore has two states (visible and hidden), which are opposite to each other.

The display property, however, decides what layout rules an element will follow. There are several different kinds of rules for how elements will lay themselves out in CSS, so there are several different values (block, inline, inline-block etc — see the documentation for these values here ).

display:none removes an element from the page layout entirely, as if it wasn’t there.

All other values for display cause the element to be a part of the page, so in a sense they’re all opposite to display:none.

But there isn’t one value that’s the direct converse of display:none - just like there's no one hair style that's the opposite of "bald".

How to add default value for html <textarea>?

Here is my jsFiddle example. this works fine:

<textarea name='awesome'>Default value</textarea>

How can I set the default value for an HTML <select> element?

Set selected="selected" for the option you want to be the default.

<option selected="selected">
3
</option>

What Is HTML's <A></A> Tag Default Display Type