Get first string before separator?

Question

I have strings with folowing structure:

7_string_12
7_string2_122
7_string3_1223

How I can get string before second "_" ?

I want my final result to be :

7_string
7_string2
7_string3

I am using explode('_', $string) and combine first two values, but my script was very slow!

score 9 · Accepted Answer · answered Jan 10 '12 at 09:44

9

$str = '7_string_12';
echo substr($str,0,strrpos($str,'_'));

echoes

7_string

no matter what's at the begining of the string

answered Jan 10 '12 at 09:44

k102

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Thanks ! I've another question! How to make this code to show me the following result : string ? That is to show string between separators. Thanks in advance ! – dido Jan 11 '12 at 11:33
@dilyan_kn `preg_match('/_(\S+)_/',$str,$m); echo $m[1];` – k102 Jan 11 '12 at 11:38
Please note, `substr($str,0,strrpos($str,'_'))` is OK if the input isn't like `7_string2_abc_123`. Because the output will be `7_string2_abc`. – yasouser Jan 02 '14 at 18:28

score 1 · Answer 2 · answered Jan 10 '12 at 09:45

If it always starts with 7_ you can try this:

$string = substr($text, 0, strpos($text, '_', 2));

The strpos() searches for the first _ starting from character 3 (= s from string). Then you use substr() to select the whole string starting from the first character to the character returned by strpos().

score 1 · Answer 3 · answered Jan 10 '12 at 09:46

1

$s1 = '7_string_12';
echo substr($s1, 0, strpos($s1, '_', 2));

answered Jan 10 '12 at 09:46

Alex Pliutau

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The assumption that the first token is always one character long is a bit dangerous. – Shlomi Noach Oct 14 '12 at 08:07

Get first string before separator?

3 Answers3