Detailed explanation of the usage of get_header to obtain the header function in WordPress development

Detailed explanation of function meaning
Call the header.php file from the current theme. Is not it simple? Well, if you are a newbie, I would like to remind you that the get here is slightly different from the get in get_children() and get_category.

get_header function declaration (definition)
In the past, when I wrote articles, I rarely wrote code for function definitions. Later, when I looked through it myself, I found that this habit was not very good, so I decided to post the function topic as long as the space allows. Convenient to browse by yourself.
The get_header function is declared (defined) around lines 24 – 36 of the wp=include/general-template.php file.

function get_header( $name = null ) {
 do_action( 'get_header', $name );
 
 $templates = array();
 if ( isset($name) )
 $templates[] = "header-{$name}.php";
 
 $templates[] = 'header.php';
 
 // Backward compat code will be removed in a future release
 if ('' == locate_template($templates, true))
 load_template( ABSPATH . WPINC . '/theme-compat/header.php');
}

The use of get_header function

<&#63;php get_header( $name ); &#63;>

is very simple. From the function declaration above, we can also see that the function only accepts one variable as a parameter.

Parameter explanation
$name, from the function declaration above, we can see that $name is a string variable used to call the header’s alias template,
For example, $name = “ab”;
That’s what we do

<&#63;php 
  $name = “ab”
  get_header( $name ); 
 
&#63;>

This will call the header-ab.php file as the header file call.

Example:

1. Simple 404 page

The following code is a simple template file specifically used to display "HTTP 404: Not Found" errors (this file should be included in your theme and named 404 .php)

<&#63;php get_header(); &#63;>
<h2>Error 404 - Not Found</h2>
<&#63;php get_sidebar(); &#63;>
<&#63;php get_footer(); &#63;>

2. Multiple headers

Display different headers for different pages

<&#63;php
if ( is_home() ) :
 get_header( 'home' );
elseif ( is_404() ) :
 get_header( '404' );
else :
 get_header();
endif;
&#63;>

These headers prepared for home and 404 should be named header-home.php and header respectively -404.php.

The above has introduced a detailed explanation of the usage of get_header to obtain the header function in WordPress development, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.