As we all are familiar with the use of pages in wordpress. Here we are discussing about the detection of pages or a specific page in wordpress. We have a default function is wordpress, that is :

<?php 

is_page(); 

?>

It is a boolean function which returns only TRUE or FALSE. If we are working in a file and wordpress like in our header.php of our current theme. If we want show different text for only pages then we will use this function in below mentioned way : 

<?php 

if( is_page() ){

echo "content to show in pages only";

}else{

echo "content to show other than pages";
}

?>

In this way we can put any code snippet in place of above text.

Check Specific Page :

If in case we want to add a condition for a specific page, like we are having so many pages in our website and we want to add a code for a specific page then we need to follow below mentioned tricks using if else statement like above : 

<?php 

is_page( 18 ); // where 18 is page id 

is_page( 'About Us' ); // where "About Us" is page title 

is_page( 'about-us' ); // where "about-us" is page slug 

?>

Check Multiple Pages :

In this reference if we need to check more than one page in same condition or in other words we want to add a condition for multiple pages of our choice, then use below mentioned code : 

<?php 

is_page( array( 18, 30, 112 ) ); // where 18, 30, 112 are page id's of multiple pages 

is_page( array( 'About Us', 'Contact Us', 'Privacy Policy' ) ); // where About Us, Contact Us, Privacy Policy are page titles  of multiple pages 

is_page( array( 'about-us', 'contact-us', 'privacy-policy' ) ); // where about-us, contact-us, privacy-policy are page slug of multiple pages 

?>

In this way working with wordpress pages becomes much easy as we are able to detect any page by just using a default wordpress function.