function countDigits($s) {
$size = strlen($s);
if ($size == 0) {
echo "String is empry";
return;
}
$digit_frequency = array(0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
for ($i = 0; $i < $size; $i++) {
if (ctype_digit($s[$i])) {
$digit_frequency[ord($s[$i]) - ord('0')]++;
}
}
for ($j = 0; $j < 10; $j++) {
echo $j . ": " . $digit_frequency[$j] . " times\n";
}
}
$s = "php23c++4523java23988rust82215";
countDigits($s);
/*
run:
0: 0 times
1: 1 times
2: 5 times
3: 3 times
4: 1 times
5: 2 times
6: 0 times
7: 0 times
8: 3 times
9: 1 times
*/