PHP computes the number of occurrences of a substring in a string substr_count ()

Instance

Calculate the number of occurrences of "world" in a string:

<?phpecho substr_count ("Hello World.") The world was nice "and" world "); >

The Substr_count () function calculates the number of occurrences of a substring in a string.

Note: Substrings are case-sensitive.

Note: This function does not count overlapping substrings (see Example 2).

Note: If the start parameter plus the length parameter is greater than the string size, the function generates a warning (see Example 3).

Grammar

Substr_count (String,substring,start,length)

parameters	description
string	required. Specifies the string to check.
substring	required. Specifies the string to retrieve.
start	optional. Specifies where to start the search in the string.
length	optional. Specifies the length of the search.

Technical details

return value:	Returns the number of occurrences of a substring in a string.
PHP version:	4 +
Update log:	In PHP 5.1, the start and length parameters have been added.

More examples

Example 1

Use all the parameters:

<?php$str = "This was nice"; Echo strlen ($STR). " <br> "; Using strlen () to return the string Lengthecho substr_count ($str, ' is '). " <br> "; The number of the Times ' is ' occurs in the Stringecho substr_count ($str, ' is ', 2). " <br> "; The string is now reduced to ' is is PHP ' echo substr_count ($str, "is", 3). " <br> "; The string is now reduced to "s was PHP" Echo substr_count ($str, "is", 3, 3). " <br> "; The string is now reduced to "s I"?>

Example 2

Overlapping sub-strings:

<?php$str = "Abcabcab"; Echo Substr_count ($str, "Abcab"); This function does not count overlapped substrings?>

Example 3

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

<?phpecho $str = "This was nice"; Substr_count ($str, ' is ', 3,9);? >

Because the length value exceeds the length of the string (3 + 9 is greater than 12). So this will output a warning.

Example:

<?php$text = ' This is a test '; Echo strlen ($text). ' <br/> '; Output echo substr_count ($text, ' is '). ' <br/> '; 2//The string is reduced to's a test ', so it prints 1echo substr_count ($text, ' is ', 3). ' <br/> ';//is actually starting from the fourth character to find out if $text contains is//the text was reduced to ' re ', so it prints 0echo substr_count ($text, ' was ', 16, 3). ' <br/> '; The text is reduced to ' s I ', so it prints 0echo substr_count ($text, ' is ', 3, 3); Generates a warning because 5+10 > 14echo substr_count ($text, ' is ', 5, 10).  ' <br/> '; Prints only 1, because it doesn ' t count overlapped subtrings$text2 = ' gcdgcdgcd '; Echo substr_count ($text 2, ' GCDGCD '). ' <br/> ';?