<?php
$a = '';
if($a exist 'some text')
echo 'text';
?>
Suppose I have the code above, how to write the statement if($a exist 'some text')?
6 Answers
Use the strpos function: http://php.net/manual/en/function.strpos.php
$haystack = "foo bar baz";
$needle = "bar";
if( strpos( $haystack, $needle ) !== false) {
echo "\"bar\" exists in the haystack variable";
}
In your case:
if( strpos( $a, 'some text' ) !== false ) echo 'text';
Note that my use of the !== operator (instead of != false or == true or even just if( strpos( ... ) ) {) is because of the "truthy"/"falsy" nature of PHP's handling of the return value of strpos.
As of PHP 8.0.0 you can now use str_contains
<?php
if (str_contains('abc', '')) {
echo "Checking the existence of the empty string will always
return true";
}
9 Comments
Leeish
Won't a non-match return 0?
Blender
false >= 0. You have to write !== false, as 0 == false.
Dai
@Blender sorry, you're right. I was thinking of the .NET
String.IndexOf which returns -1 in event of a non-match. I've corrected my answer.
Pathros
And
stripos() for insensitive string comparison ...Dai
@PadronizaçãoSA The
! operator will affect the falsiness of the return value from strpos which means === won't work the way it's intended. |
Empty strings are falsey, so you can just write:
if ($a) {
echo 'text';
}
Although if you're asking if a particular substring exists in that string, you can use strpos() to do that:
if (strpos($a, 'some text') !== false) {
echo 'text';
}
1 Comment
Dave
Also if you want it to find "Some Text", "SOME TEXT", etc. use
stripos (which is case insensitive)http://php.net/manual/en/function.strpos.php I think you are wondiner if 'some text' exists in the string right?
if(strpos( $a , 'some text' ) !== false)
Comments
If you need to know if a word exists in a string you can use this. As it is not clear from your question if you just want to know if the variable is a string or not. Where 'word' is the word you are searching in the string.
if (strpos($a,'word') !== false) {
echo 'true';
}
or use the is_string method. Whichs returns true or false on the given variable.
<?php
$a = '';
is_string($a);
?>
Comments
You can use the == comparison operator to check if the variable is equal to the text:
if( $a == 'some text') {
...
You can also use strpos function to return the first occurrence of a string:
<?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 $pos";
}
Comments
You can use strpos() or stripos() to check if the string contain the given needle. It will return the position where it was found, otherwise will return FALSE.
Use the operators === or `!== to differ FALSE from 0 in PHP.
if($a == 'some text'). Here some more info over operators: php.net/manual/en/language.operators.comparison.phpif(strlen($a) > 0) echo 'text';or if your concern is to check for specific word the follow the @Dai answer.