Alter the WordPress post title placeholder text

alter-wp-post-title-placeholder.php

<?php
/**
 * Alter the enter title here placeholder text.
 * This is on the WordPress post edit screens.
 *
 * @param  string $title The is the current placeholder string.
 * @return string        The modified placeholder string.
 */
function hd_title_here( $title ) {

	// set a new string for the placeholder text.
	$title = __( 'Enter article title here.', 'text-domain' );

	// return the title back to the hook.
	return $title;

}
add_action( 'enter_title_here', 'hd_title_here', 10 );