PHP : How to check if the string only contains 1 alphabet?

Posted on 2012-04-12
Last Modified: 2012-06-27
Hie all,

How to do I check if the string only contains 1 alphabet? For example,

$string = 'AAAAAB'  - false
$string = 'AAAAAA'  - true

I have tried using strpos, preg_match but couldnt suit my needs. I just need to make sure that there is all A in the string.

Question by:bosscat
LVL 14

Assisted Solution

by:Scott Madeira
Scott Madeira earned 200 total points
ID: 37839488
This worked for me for some simple examples....


$string = 'AAABBAA';

if (strlen($string) +1 == count(explode(substr($string, 1,1), $string))){
	// They are the same
	echo 'All same characters';
} else {
	// They are different
	echo 'Some different characters';

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LVL 13

Accepted Solution

Phil Phillips earned 200 total points
ID: 37840333
This is a slightly less complicated variant of the answer above.


$string = 'AAABBAA';

if (strlen($string) == substr_count($string, $string{0})) {
   // They are the same
   echo 'All same characters';
else {
   // They are different
   echo 'Some different characters';


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Note that both examples are case-sensitive.  So, if you want 'aaaAA' to return 'true', then you could convert the string to lower case (strtolower()) when running the check.

Author Closing Comment

ID: 37840653
Thank you guys... Both ways work excellent.

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