Check if whole string contains same character

Question

I want to check if a string contains a character repeated zero or more times, for example:

• If my string is aaaaaa, bbbb, c or ***** it must return true.

• If it contains aaab, cd, or **%*** it must return false.

In other words, if the string has 2 or more unique characters, it must return false.

How to go about this in PHP?

PS: Is there a way to do it without RegEx?

Answer 1

You could split on every character then count the array for unique values.

if(count(array_count_values(str_split('abaaaa'))) == 1) {
    echo 'True';
} else {
    echo 'false';
}

Demo: https://eval.in/760293

Answer 2

count(array_unique(explode('', string)) == 1) ? true : false;

Answer 3

You can use a regular expression with a back-reference:

if (preg_match('/^(.)\1*$/', $string)) {
    echo "Same characters";
}

Or a simple loop:

$same = true;
$firstchar = $string[0];
for ($i = 1; $i < strlen($string); $i++) {
    if ($string[$i] != $firstchar) {
        $same = false;
        break;
    }
}