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(PHP 4, PHP 5, PHP 7, PHP 8)
strpos — Find the position of the first occurrence of a substring in a string
Find the numeric position of the first occurrence of
needle
in the haystack
string.
haystack
The string to search in.
needle
The string to search for.
Antes do PHP 8.0.0, se needle
não for uma string, ela será convertida
para um número inteiro e aplicada como o valor ordinal de um caractere.
Este comportamento tornou-se defasado a partir do PHP 7.3.0 e depender dele é altamente
desaconselhado. Dependendo do comportamento pretendido, o parâmetro
needle
deve ser explicitamente convertido em string
ou uma chamada explícita para chr() deve ser realizada.
offset
If specified, search will start this number of characters counted from the beginning of the string. If the offset is negative, the search will start this number of characters counted from the end of the string.
Returns the position of where the needle exists relative to the beginning of
the haystack
string (independent of offset).
Also note that string positions start at 0, and not 1.
Returns false
if the needle was not found.
Esta função pode
retornar o valor booleano false
, mas também pode retornar um valor não booleano que pode ser
avaliado como false
. Leia a seção sobre Booleanos para mais
informações. Use o operador
=== para testar o valor retornado por esta
função.
Versão | Descrição |
---|---|
8.0.0 |
O parâmetro needle agora aceita uma string vazia.
|
8.0.0 |
Passing an int as needle is no longer supported.
|
7.3.0 |
Passing an int as needle has been deprecated.
|
7.1.0 |
Support for negative offset s has been added.
|
Exemplo #1 Using ===
<?php
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);
// Note our use of ===. Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
if ($pos === false) {
echo "The string '$findme' was not found in the string '$mystring'";
} else {
echo "The string '$findme' was found in the string '$mystring'";
echo " and exists at position $pos";
}
?>
Exemplo #2 Using !==
<?php
$mystring = 'abc';
$findme = 'a';
$pos = strpos($mystring, $findme);
// The !== operator can also be used. Using != would not work as expected
// because the position of 'a' is 0. The statement (0 != false) evaluates
// to false.
if ($pos !== false) {
echo "The string '$findme' was found in the string '$mystring'";
echo " and exists at position $pos";
} else {
echo "The string '$findme' was not found in the string '$mystring'";
}
?>
Exemplo #3 Using an offset
<?php
// We can search for the character, ignoring anything before the offset
$newstring = 'abcdef abcdef';
$pos = strpos($newstring, 'a', 1); // $pos = 7, not 0
?>
Nota: Esta função é compatível com dados binários.