<?php
$text = 'This is a test' ;
echo strlen ( $text ); // 14

echo substr_count ( $text , 'is' ); // 2

// the string is reduced to 's is a test', so it prints 1
echo substr_count ( $text , 'is' , 3 );

// the text is reduced to 's i', so it prints 0
echo substr_count ( $text , 'is' , 3 , 3 );

// generates a warning because 5+10 > 14
echo substr_count ( $text , 'is' , 5 , 10 );


// prints only 1, because it doesn't count overlapped subtrings
$text2 = 'gcdgcdgcd' ;
echo substr_count ( $text2 , 'gcdgcd' );
?>