Regex, PHP pregmatch make function how to return true if string start with start_to_date

Question

Possible Duplicate:
PHP: How to check if a string starts with a specified string?

I am struggling to create a function to check this string starting from start_to_date or not, below is my implement.

$string = 'start_to_date-blablablabla';
if(cek_my_str($string)){
   echo "String is OK";
}

// tes again
$string2 = 'helloworld-blablablabla';
if(cek_my_str($string2)){
   echo "String not OK";
}

function cek_my_str($str){
   // how code to return true if $str is string which start with start_to_date
}

Thanx.

Please do research before asking questions that have been asked and answered again or to which the answer is easy to find in search engines. — Gordon, Feb 02 '13 at 10:27
http://php.net/strpos - can we close the question now? Thanks. — Gordon, Feb 02 '13 at 10:30
@AlanIchal: You need to **BE NICE** here on Stack Overflow. "Your answer is suck man" is not considered "nice". — ThiefMaster, Feb 02 '13 at 11:56

score 3 · Answer 1 · edited Feb 02 '13 at 11:05

3

To do it with Regex, you would do:

return preg_match('/^start_to_date/', $str);

Key reference: http://www.regular-expressions.info/

However, the PHP Manual for preg_match states

Do not use preg_match() if you only want to check if one string is contained in another string. Use strpos() or strstr() instead as they will be faster.

By the way, you should look into unit testing: http://www.phpunit.de/manual/current/en/

This is a way of encapsulating exactly what you are doing in reusable tests.

edited Feb 02 '13 at 11:05

Gordon

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answered Feb 02 '13 at 10:24

leftclickben

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And why is the question down voted too? It is very basic level but people have to start somewhere, right? – leftclickben Feb 02 '13 at 10:26
Re: question getting downvoted, okay I get that. Re: my answer getting downvoted, and your comment on the question (which I don't have enough rep to reply to) "people got downvoted because they suggest overly complicated solutions instead of simply suggesting strpos" Well the question **stated** `preg_match`, so I believe that this is a starting point, not an ending point. Clearly there is something after the "start_to_date" token, which in likelihood will need to be further parsed. It seems like this person is studying regular expressions, so telling them to use `strpos` is invalid. – leftclickben Feb 02 '13 at 10:47
Anyway if it's a duplicate, why not just mark it as such? – leftclickben Feb 02 '13 at 10:49
Well the title stated both "regex" and "preg_match" so I'm not making any assumptions. – leftclickben Feb 02 '13 at 10:50
So you did, voted. (for the record at least lol) – leftclickben Feb 02 '13 at 10:51

score 3 · Answer 2 · answered Feb 02 '13 at 10:40

3

In this case the best thing to do is:

if(strpos($string, 'start_to_date') === 0) { ... }

strpos() checks if 'start_to_date' is on position 0 (beginning)

answered Feb 02 '13 at 10:40

Nicholas Ruunu

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score 0 · Answer 3 · answered Feb 02 '13 at 10:24

0

how about:

function cek_my_str($str){
    return preg_match('/^start_to_date/', $str)
}

answered Feb 02 '13 at 10:24

Toto

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Any reason for the downvote? – Toto Feb 02 '13 at 10:26
OK this solved. tnx man. I just add if !preg_match blabla return false and default return true. Thanks. – Loren Ramly Feb 02 '13 at 10:43

score 0 · Answer 4 · answered Feb 02 '13 at 10:28

0

function cek_my_str($str){
   $find = 'start_to_date';
   $substr = substr($str, 0, strlen($find));
   if($substr == $find){
    return true;
   }else{
    return false;
   }
}

answered Feb 02 '13 at 10:28

Regex, PHP pregmatch make function how to return true if string start with start_to_date

4 Answers4