CODEWITHSUNDEEP
phpregexpreg-match
liu jin long
liu jin long

Reputation: 69

regex help about multiple string with ,

I have a string of tfa_2,tfa_3,tfa_4 and I have a regex of /^tfa_\d+/

How can I make it select all the tfa_1...tfa_999 and disregard the comma?

Thanks.

Upvotes: 1

Views: 34

Answers (2)

nhahtdh
nhahtdh

Reputation: 56829

Assuming the input contains the exact format ^tfa_\d+(,tfa_\d+)*$ and no limit on the number after tfa_

The simplest solution is to use explode:

$tokens = explode(",", "tfa_2,tfa_3,tfa_4");

You can also use preg_split or preg_match, but they are overkill under this assumption:

$tokens = preg_split('/,/', "tfa_2,tfa_3,tfa_4");

$retcode = preg_match_all('/tfa_\d+/', "tfa_2,tfa_3,tfa_4", $tokens);

Assuming the input contains the exact format ^[^,]+(,[^,]+)*$, no quoted token, and no limit on the number after tfa_

You need to assert that tfa_\d+ is not preceded or suceeded by a non-separator (non-comma character) to prevent htfa_345, tfa_456xxx, -tfa_34 from being considered a match:

$retcode = preg_match_all('/(?<![^,])tfa_\d+(?![^,])/', "tfa_2,tfa_3,tfa_4,htfa_345,tfa_456xxx,-tfa_34", $tokens);

Alternate solution, by explode the string along , and use array_filter to filter out unwanted fields:

$fields = explode(",", "tfa_2,tfa_3,tfa_4,htfa_345,tfa_456xxx,-tfa_34");
$tokens = array_filter($fields, function ($v) {
    return preg_match('/^tfa_\d+$/', $v) == 1;
});

Assuming the input contains the exact format ^[^,]+(,[^,]+)*$, no quoted token, and the number after tfa_ can only be 1 to 999

Just modify the regex a bit to limit the number ([1-9]\d{0,2}):

$retcode = preg_match_all('/(?<![^,])tfa_[1-9]\d{0,2}(?![^,])/', "tfa_2,tfa_3,tfa_4456,htfa_345,tfa_456xxx,-tfa_34", $tokens);

Similar modification for explode + array_filter solution:

$fields = explode(",", "tfa_2,tfa_3,tfa_4456,htfa_345,tfa_456xxx,-tfa_34");
$tokens = array_filter($fields, function ($v) {
    return preg_match('/^tfa_[1-9]\d{0,2}$/', $v) == 1;
});

Upvotes: 2

James
James

Reputation: 138

From the update and the comments,

/(tfa_\d{1,3})+/g

In PHP:

$re = "/(tfa_\\d{1,3})+/"; 
$str = "tfa_1,tfa_002,tfa_999,tfa_xxx"; 

preg_match_all($re, $str, $matches);

Will match tfa_1, tfa_002, tfa_999 but not tfa_xxx or tfa_

Upvotes: 1

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