WPMU DEV Write and activate a function

apply_filters.php

echo apply_filters( 'wpmu_filter_hook', '<h3>Latest Posts</h3>' );

comments.php

/************************************************************************
wpmu_add_google_fonts - register google fonts
************************************************************************/

conditional.php

/*****************************************************************************
wpmu_posted_on - add dates on single posts
*****************************************************************************/
function wpmu_posted_on() {

	if ( is_singular( 'post' ) ) {?>
		
		<section class="entry-meta">
			<?php echo get_the_date(); ?>
		</section>
	
	<?php }
	
}
add_action ( 'wpmu_before_content', 'wpmu_posted_on' );

conditional_wrong1.php

/*****************************************************************************
wpmu_posted_on - add dates on single posts - THIS IS INCORRECT
*****************************************************************************/
function wpmu_posted_on() {
		
		<section class="entry-meta">
			<?php echo get_the_date(); ?>
		</section>
		
}
if ( is_singular( 'post' ) ) {
  add_action ( 'wpmu_before_content', 'wpmu_posted_on' );
}

conditional_wrong2.php

/*****************************************************************************
wpmu_posted_on - add dates on single posts - THIS IS INCORRECT
*****************************************************************************/
if ( is_singular( 'post' ) ) {

  function wpmu_posted_on() {
		
		<section class="entry-meta">
			<?php echo get_the_date(); ?>
		</section>
	}
}

add_action ( 'wpmu_before_content', 'wpmu_posted_on' );

do_action.php

do_action( 'wpmu_before_content' );

function_attached_to_filter.php

/*****************************************************************************
wpmu_heading - override title of latest posts section
*****************************************************************************/
function wpmu_heading() {
		
		<h3>Recent Posts</h3>

}

add_filter ( 'wpmu_filter_hook', 'wpmu_heading' );

function_contents.php

wp_register_style( 'googleFonts', 'https://fonts.googleapis.com/css?family=Assistant|Oswald:300');	
wp_enqueue_style( 'googleFonts');

function_opening.php

function wpmu_add_google_fonts() {

}

WordPress_action_hook.php

add_action( 'wp_enqueue_scripts', 'wpmu_add_google_fonts' );

wpmu_add_google_fonts_full.php

/************************************************************************
wpmu_add_google_fonts - register google fonts
************************************************************************/
function wpmu_add_google_fonts {
  wp_register_style( 'googleFonts', 'https://fonts.googleapis.com/css?family=Assistant|Oswald:300');	
  wp_enqueue_style( 'googleFonts');
 }

add_action( 'wp_enqueue_scripts', 'wpmu_add_google_fonts' );

wpmu_add_google_fonts_function.php

/************************************************************************
wpmu_add_google_fonts - register google fonts
************************************************************************/
function wpmu_add_google_fonts {
  wp_register_style( 'googleFonts', 'https://fonts.googleapis.com/css?family=Assistant|Oswald:300');	
  wp_enqueue_style( 'googleFonts');
 }

wpmu_posted_on.php

/*****************************************************************************
wpmu_posted_on - add dates on single posts
*****************************************************************************/
function rachelmcc_posted_on() {
		
		<section class="entry-meta">
			<?php echo get_the_date(); ?>
		</section>
		
}

wpmu_posted_on_activate.php

rachelmcc_posted_on();

wpmu_posted_on_hooked.php

/*****************************************************************************
wpmu_posted_on - add dates on single posts
*****************************************************************************/
function rachelmcc_posted_on() {
		
		<section class="entry-meta">
			<?php echo get_the_date(); ?>
		</section>
		
}
add_action( 'wpmu_before_content', 'rachelmcc_posted_on' );