php regex match string code example

Example 1: regex php

<?php
// First Verif your regex code with https://regex101.com/
$str = "Visit W3Schools";
$pattern = "/w3schools/i";
echo preg_match($pattern, $str); // Outputs 1

// test email with REGEX
if (!preg_match("/[-0-9a-zA-Z.+_]+@[-0-9a-zA-Z.+_]+.[a-zA-Z]{2,4}/", $emailAddress)){
    //Email address is invalid.
}

// use filter var to valide Email
if(filter_var($emailAddress, FILTER_VALIDATE_EMAIL)) 
{
     //The email address is valid.
} else{
     //The email address is invalid.
}


?>

Example 2: preg_match in php

<?php
//Syntex : int preg_match( $pattern, $input, $matches, $flags, $offset)
  
// Declare a variable and initialize it 
$str = "Check For Testing."; 
  
// case-Insensitive search for the word "Check" 
if (preg_match("/\bCheck\b/i", $str, $match))  
    echo "Matched!"; 
else
    echo "not matched";   
  

// Output : Matched
?>

Example 3: find substring regx php

if (preg_match("/\bweb\b/i", "PHP is the web scripting language of choice.")) {
    echo "A match was found.";
} else {
    echo "A match was not found.";
}