substr_count

Definition and usage

substr_count() function calculates the number of times a substring appears in a string.

Comment: Substrings are case sensitive.

Note: This function does not count overlapping substrings (see Example 3).

Note: If the start parameter plus length parameter is greater than the string length, the function generates a warning (see Example 4).

Example

Example 1

Calculate the number of times "Shanghai" appears in a string:

 <?php
echo substr_count ( "I love Shanghai. Shanghai is the biggest city in china." , "Shanghai" ) ;
?>

Try it yourself

Example 2

Use all parameters:

 <?php
$str = "This is nice" ;
echo strlen ( $str ) . "<br>" ; // Use strlen() to return the string length
echo substr_count ( $str , "is" ) . "<br>" ; // Number of times "is" appears in the string
echo substr_count ( $str , "is" , 2 ) . "<br>" ; // The string is reduced to "is is nice"
echo substr_count ( $str , "is" , 3 ) . "<br>" ; // The string is reduced to "s is nice"
echo substr_count ( $str , "is" , 3 , 3 ) . "<br>" ; // The string is reduced to "si"
?>

Try it yourself

Example 3

Overlapping substrings:

 <?php
$str = "abcabcab" ;
echo substr_count ( $str , "abcab" ) ; // This function does not count overlapping substrings
?>

Try it yourself

Example 4

If the start and length parameters exceed the string length, the function outputs a warning:

 <?php
echo $str = "This is nice" ;
substr_count ( $str , "is" , 3 , 9 ) ;
?>

Because the length value exceeds the length of the string (3 + 9 is greater than 12), a warning is outputted using it.

grammar

 substr_count ( string , substring , start , length )