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!

Meyer

Answer 1

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

echoes

7_string

no matter what's at the begining of the string

Mcchesney

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 ! – Meyer

@dilyan_kn preg_match('/_(\S+)_/',$str,$m); echo $m[1]; – Mcchesney

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. – Pushing

Answer 2

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().

Edgerton

Answer 3

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

Jugurtha

The assumption that the first token is always one character long is a bit dangerous. – Haydeehayden