function all_characters_are_the_same($s) {
$len = strlen($s);
for ($i = 1; $i < $len; $i++) {
if ($s[$i] != $s[0]) {
return false;
}
}
return true;
}
$s = "aaaaa";
if (all_characters_are_the_same($s)) {
echo "Yes";
}
else {
echo "No";
}
/*
run:
Yes
*/