See:
$a = 'How are you?';if ($a contains 'are') echo 'true';Say I person the codification supra, what is the accurate manner to compose the message if ($a contains 'are')?
Present with PHP Eight you tin bash this utilizing str_contains:
if (str_contains('How are you', 'are')) { echo 'true';}Delight line: The str_contains relation volition ever instrument actual if the $needle (the substring to hunt for successful your drawstring) is bare.
$haystack = 'Hello';$needle = '';if (str_contains($haystack, $needle)) { echo "This returned true!";}You ought to archetypal brand certain the $needle (your substring) is not bare.
$haystack = 'How are you?';$needle = '';if ($needle !== '' && str_contains($haystack, $needle)) { echo "This returned true!";} else { echo "This returned false!";}Output: This returned false!
It's besides worthy noting that the fresh str_contains relation is lawsuit-delicate.
$haystack = 'How are you?';$needle = 'how';if ($needle !== '' && str_contains($haystack, $needle)) { echo "This returned true!";} else { echo "This returned false!";}Output: This returned false!
Earlier PHP Eight
You tin usage the strpos() relation which is utilized to discovery the incidence of 1 drawstring wrong different 1:
$haystack = 'How are you?';$needle = 'are';if (strpos($haystack, $needle) !== false) { echo 'true';}Line that the usage of !== false is deliberate (neither != false nor === true volition instrument the desired consequence); strpos() returns both the offset astatine which the needle drawstring begins successful the haystack drawstring, oregon the boolean false if the needle isn't recovered. Since Zero is a legitimate offset and Zero is "falsey", we tin't usage easier constructs similar !strpos($a, 'are').
You might usage daily expressions arsenic it's amended for statement matching in contrast to strpos, arsenic talked about by another customers. A strpos cheque for are volition besides instrument actual for strings specified arsenic: fare, attention, look, and so forth. These unintended matches tin merely beryllium averted successful daily look by utilizing statement boundaries.
A elemental lucifer for are might expression thing similar this:
$a = 'How are you?';if (preg_match('/\bare\b/', $a)) { echo 'true';}Connected the show broadside, strpos is astir 3 instances sooner. Once I did 1 cardinal compares astatine erstwhile, it took preg_match 1.5 seconds to decorativeness and for strpos it took Zero.5 seconds.
Edit:Successful command to hunt immoderate portion of the drawstring, not conscionable statement by statement, I would urge utilizing a daily look similar
$a = 'How are you?';$search = 'are y';if(preg_match("/{$search}/i", $a)) { echo 'true';}The i astatine the extremity of daily look adjustments daily look to beryllium lawsuit-insensitive, if you bash not privation that, you tin permission it retired.
Present, this tin beryllium rather problematic successful any instances arsenic the $hunt drawstring isn't sanitized successful immoderate manner, I average, it mightiness not walk the cheque successful any instances arsenic if $search is a person enter they tin adhd any drawstring that mightiness behave similar any antithetic daily look...
Besides, present's a large implement for investigating and seeing explanations of assorted daily expressions Regex101
To harvester some units of performance into a azygous multi-intent relation (together with with selectable lawsuit sensitivity), you might usage thing similar this:
function FindString($needle,$haystack,$i,$word){ // $i should be "" or "i" for case insensitive if (strtoupper($word)=="W") { // if $word is "W" then word search instead of string in string search. if (preg_match("/\b{$needle}\b/{$i}", $haystack)) { return true; } } else { if(preg_match("/{$needle}/{$i}", $haystack)) { return true; } } return false; // Put quotes around true and false above to return them as strings instead of as bools/ints.}1 much happening to return successful head, is that \b volition not activity successful antithetic languages another than nation.
The mentation for this and the resolution is taken from present:
\brepresents the opening oregon extremity of a statement (Statement Bound). Thisregex would lucifer pome successful an pome pastry, however wouldn’t lucifer pome inpineapple, applecarts oregon bakeapples.However astir “café”? However tin we extract the statement “café” successful regex?Really, \bcafé\b wouldn’t activity. Wherefore? Due to the fact that “café” containsnon-ASCII quality: é. \b tin’t beryllium merely utilized with Unicode specified arsenicसमुद्र, 감사, месяц and 😉 .
Once you privation to extract Unicode characters, you ought to directlydefine characters which correspond statement boundaries.
The reply:
(?<=[\s,.:;"']|^)UNICODE_WORD(?=[\s,.:;"']|$)
Truthful successful command to usage the reply successful PHP, you tin usage this relation:
function contains($str, array $arr) { // Works in Hebrew and any other unicode characters // Thanks https://medium.com/@shiba1014/regex-word-boundaries-with-unicode-207794f6e7ed // Thanks https://www.phpliveregex.com/ if (preg_match('/(?<=[\s,.:;"\']|^)' . $word . '(?=[\s,.:;"\']|$)/', $str)) return true;}And if you privation to hunt for array of phrases, you tin usage this:
function arrayContainsWord($str, array $arr){ foreach ($arr as $word) { // Works in Hebrew and any other unicode characters // Thanks https://medium.com/@shiba1014/regex-word-boundaries-with-unicode-207794f6e7ed // Thanks https://www.phpliveregex.com/ if (preg_match('/(?<=[\s,.:;"\']|^)' . $word . '(?=[\s,.:;"\']|$)/', $str)) return true; } return false;}Arsenic of PHP Eight.Zero.Zero you tin present usage str_contains
<?php if (str_contains('abc', '')) { echo "Checking the existence of the empty string will always" return true; }Successful PHP, figuring out whether or not a drawstring incorporates a circumstantial substring is a communal project successful assorted purposes, specified arsenic information validation, contented filtering, and hunt performance. Effectively checking for the beingness of a substring tin importantly contact the show and accuracy of your scripts. This article volition research assorted strategies disposable successful PHP to execute this, offering elaborate explanations, codification examples, and champion practices to guarantee you take the about due resolution for your wants. Whether or not you're gathering a elemental book oregon a analyzable exertion, knowing these strategies is indispensable for effectual drawstring manipulation.
However to Find if a Drawstring Incorporates a Substring successful PHP
PHP affords respective features to cheque if a drawstring incorporates a circumstantial substring. The about generally utilized features are strpos(), str_contains() (disposable since PHP Eight.Zero), and strstr(). All relation has its ain strengths and weaknesses, making them appropriate for antithetic eventualities. Knowing the nuances of all relation is cardinal to penning businesslike and dependable codification. Selecting the correct methodology tin optimize your codification's show and guarantee it behaves arsenic anticipated, particularly once dealing with ample strings oregon predominant substring checks. By mastering these strategies, you tin confidently grip immoderate drawstring manipulation project successful your PHP initiatives.
Utilizing strpos() to Discovery a Substring
The strpos() relation successful PHP is utilized to discovery the assumption of the archetypal prevalence of a substring inside a drawstring. It returns the numeric assumption of the archetypal prevalence oregon mendacious if the substring is not recovered. It's important to retrieve that strpos() is lawsuit-delicate. A communal error is not utilizing the strict examination (!==) function once checking the instrument worth due to the fact that if the substring is recovered astatine the opening of the drawstring (assumption Zero), a free examination (!=) would measure to mendacious. This tin pb to surprising behaviour successful your codification. So, ever usage !== to precisely find if the substring exists.
<?php $string = "Hello World!"; $substring = "World"; if (strpos($string, $substring) !== false) { echo "Substring found!"; } else { echo "Substring not found."; } ?> Using str_contains() for Substring Detection
Launched successful PHP Eight.Zero, the str_contains() relation supplies a much simple and readable manner to cheque if a drawstring incorporates a substring. Dissimilar strpos(), it returns a boolean worth (actual oregon mendacious), indicating whether or not the substring is immediate. This eliminates the demand for strict examination operators and makes the codification cleaner and simpler to realize. The simplicity of str_contains() reduces the possible for errors and improves codification maintainability. For initiatives moving connected PHP Eight.Zero oregon future, str_contains() is mostly most popular owed to its readability and diminished hazard of logical errors.
<?php $string = "Hello World!"; $substring = "World"; if (str_contains($string, $substring)) { echo "Substring found!"; } else { echo "Substring not found."; } ?> Earlier continuing, present is an absorbing article: Cheque if a mounted cardinal already exists palmy a dictionary
Using strstr() to Find Substrings
The strstr() relation finds the archetypal prevalence of a drawstring inside different drawstring and returns the condition of the drawstring from that component to the extremity. If the substring is not recovered, it returns mendacious. 1 cardinal quality from strpos() is that strstr() returns the existent substring instead than its assumption. This tin beryllium utile if you demand to extract the condition of the drawstring last the substring. Similar strpos(), strstr() is besides lawsuit-delicate. Once utilizing strstr(), beryllium alert that its instrument worth wants to beryllium checked cautiously to debar possible kind-associated points, akin to these encountered with strpos(). Larn much astir strstr() connected the PHP documentation.
<?php $string = "Hello World!"; $substring = "World"; if (strstr($string, $substring) !== false) { echo "Substring found!"; } else { echo "Substring not found."; } ?> Examination of Strategies for Substring Checks
Selecting the correct methodology for checking if a drawstring incorporates a substring relies upon connected the circumstantial necessities of your exertion. strpos() is wide suitable and businesslike, however requires cautious dealing with of its instrument worth. str_contains() affords simplicity and readability for PHP Eight.Zero+ initiatives. strstr() is utile once you demand to extract the condition of the drawstring last the substring. See the pursuing examination array to brand an knowledgeable determination based mostly connected elements specified arsenic PHP interpretation compatibility, easiness of usage, and circumstantial performance.
| Relation | PHP Interpretation | Instrument Worth | Lawsuit-Delicate | Usage Lawsuit |
|---|---|---|---|---|
strpos() | PHP Four+ | Integer (assumption) oregon false | Sure | Uncovering the assumption of a substring. |
str_contains() | PHP Eight.Zero+ | Boolean (true oregon false) | Sure | Elemental substring beingness cheque. |
strstr() | PHP Four+ | Drawstring (from substring to extremity) oregon false | Sure | Extracting the condition of the drawstring last the substring. |
Successful abstract, strpos() is a versatile action for older PHP variations, piece str_contains() affords a much contemporary and simple attack successful PHP Eight.Zero and future. strstr() is generous once you demand to retrieve the portion of the drawstring that follows the substring.
Knowing however to efficaciously usage PHP for drawstring manipulation is important for net improvement. By choosing the about due methodology for your circumstantial wants, you tin compose cleaner, much businesslike, and much maintainable codification.
Successful decision, figuring out if a drawstring incorporates a circumstantial substring successful PHP tin beryllium achieved utilizing respective strategies, all with its ain benefits and concerns. The strpos() relation is a versatile prime, offering the assumption of the substring if recovered. For PHP Eight.Zero and future, str_contains() affords a cleaner and much readable boolean cheque. Moreover, strstr() tin beryllium utilized to extract the condition of the drawstring last the substring. Selecting the correct methodology relies upon connected your circumstantial necessities and PHP interpretation. Appropriate usage of these strategies ensures businesslike and close drawstring manipulation successful your PHP purposes. By mastering these strategies, builders tin confidently grip assorted drawstring-associated duties. Research much astir PHP strings.