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substr_replace> <substr_compare
[edit] Last updated: Wed, 19 Jun 2013

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substr_count

(PHP 4, PHP 5)

substr_countConta o número de ocorrências de uma substring

Descrição

int substr_count ( string $haystack , string $needle [, int $offset [, int $length ]] )

substr_count() retorna o número de vezes que a substring needle ocorre na string. Note que needle faz distinção de maiúscula e minúscula.

Nota:

Esta função não conta substrings sobrepostas. Veja o exemplo abaixo!

Parâmetros

haystack

A string onde será feita a busca

needle

A substring a ser procurada

offset

O índice onde inicia a contagem

length

O valor máximo depois do índice especificado para buscar pela substring. Mostra um aviso se o tamanho do índice for maior que o tamanho de haystack.

Valor Retornado

Esta função retorna um integer.

Changelog

Versão Descrição
5.1.0 Adiciona os parâmetros offset e length

Exemplos

Exemplo #1 Exemplo da substr_count()

<?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'33);

// generates a warning because 5+10 > 14
echo substr_count($text'is'510);


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

Veja Também

  • count_chars() - Retorna informações sobre os caracteres usados numa string
  • strpos() - Encontra a posição da primeira ocorrência de uma string
  • substr() - Retorna uma parte de uma string
  • strstr() - Encontra a primeira ocorrencia de uma string



substr_replace> <substr_compare
[edit] Last updated: Wed, 19 Jun 2013
 
add a note add a note User Contributed Notes substr_count - [10 notes]
up
1
flobi at flobi dot com
6 years ago
Making this case insensitive is easy for anyone who needs this.  Simply convert the haystack and the needle to the same case (upper or lower).

substr_count(strtoupper($haystack), strtoupper($needle))
up
4
jrhodes at roket-enterprises dot com
4 years ago
It was suggested to use

substr_count ( implode( $haystackArray ), $needle );

instead of the function described previously, however this has one flaw.  For example this array:

array (
  0 => "mystringth",
  1 => "atislong"
);

If you are counting "that", the implode version will return 1, but the function previously described will return 0.
up
2
info at fat-fish dot co dot il
6 years ago
a simple version for an array needle (multiply sub-strings):
<?php

function substr_count_array( $haystack, $needle ) {
    
$count = 0;
     foreach (
$needle as $substring) {
         
$count += substr_count( $haystack, $substring);
     }
     return
$count;
}
?>
up
0
chrisstocktonaz at gmail dot com
3 years ago
In regards to anyone thinking of using code contributed by zmindster at gmail dot com

Please take careful consideration of possible edge cases with that regex, in example:

$url = 'http://w3.host.tld/path/to/file/..../file.extension';
$url = 'http://w3.host.tld/path/to/file/../file.extension?malicous=....';

This would cause a infinite loop and for example be a possible entry point for a denial of service attack. A correct fix would require additional code, a quick hack would be just adding a additional check, without clarity or performance in mind:

...
$i = 0;
while (substr_count($url, '../') && ++$i < strlen($url))
...

-Chris
up
0
XinfoX X at X XkarlX X-X XphilippX X dot X XdeX
9 years ago
Yet another reference to the "cgcgcgcgcgcgc" example posted by "chris at pecoraro dot net":

Your request can be fulfilled with the Perl compatible regular expressions and their lookahead and lookbehind features.

The example

 $number_of_full_pattern = preg_match_all('/(cgc)/', "cgcgcgcgcgcgcg", $chunks);

works like the substr_count function. The variable $number_of_full_pattern has the value 3, because the default behavior of Perl compatible regular expressions is to consume the characters of the string subject that were matched by the (sub)pattern. That is, the pointer will be moved to the end of the matched substring.
But we can use the lookahead feature that disables the moving of the pointer:

 $number_of_full_pattern = preg_match_all('/(cg(?=c))/', "cgcgcgcgcgcgcg", $chunks);

In this case the variable $number_of_full_pattern has the value 6.
Firstly a string "cg" will be matched and the pointer will be moved to the end of this string. Then the regular expression looks ahead whether a 'c' can be matched. Despite of the occurence of the character 'c' the pointer is not moved.
up
0
gigi at phpmycoder dot com
4 years ago
below was suggested a function for substr_count'ing an array, yet for a simpler procedure, use the following:

<?php
substr_count
( implode( $haystackArray ), $needle );
?>
up
0
danjr33 at gmail dot com
5 years ago
I ran into trouble using this function when I moved a script from a server with PHP5 to a server with only PHP4.
As the last two parameters were added with 5.1.0, I wrote a substitute function:
<?php
function substr_count5($str,$search,$offset,$len) {
    return
substr_count(substr($str,$offset,$len),$search);
}
?>
Use it exactly as substr_count() is used in PHP5. (This will work in PHP5 as well.)
up
-1
Douglas Dennis
1 month ago
It was previously noted that if you use "substr_count(implode(array))" with this array:

array (
  0 => "mystringth",
  1 => "atislong"
);

The following would result:
"If you are counting "that", the implode version will return 1, but the function previously described will return 0."

You can fix this by using substr_count(implode(' ', array), 'that') which will result in the following string: "mystringth atislong".
up
-1
Anonymous
4 years ago
It should be noted that unlike the other substr functions, the offset value cannot be a negative value.

<?php
echo substr_count('abcdefg', 'efg', 4, 3); // 1
echo substr_count('abcdefg', 'efg', -3, 3); // warning
?>
up
-3
zmindster at gmail dot com
4 years ago
For some who seeked for an easy way to resolve URL composed of /../ like http://w3.host.tld/path/to/the/file/../../file.extension, here is a solution

<?php
$url
= 'http://w3.host.tld/path/to/file/../file.extension';

while (
substr_count($url, "../"))
{
   
$url = preg_replace('#/[^/]+/\.\.#', '', $url);
}
//outputs 'http://w3.host.tld/path/to/file.extension'
?>

and seems to work perfectly!

 
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