Code Snippet: Print All Integers in a String

Within these castle walls be forged Mavens of Computer Science ...

— Merlin, The Coder

Print All Integers in a String

Swift

var line : String?
repeat {
    line = readLine()
    if let text = line {
        for character in text {
            if ("0" ... "9").contains(character) {
                print(character)
            }
        }
    }
} while line != nil

Python

string = input()
for char in string:
    if char.isdigit():
        print(char)

Source

Java

// Unfinished code

String s = "ab3bk49dn3"; // random string
String nums = ""; // string that will contain the numbers from s in order

// Convert s to a character array
char[] chars = s.toCharArray();

// Loop through all the chars to find the numbers
for(int i=0; i<chars.length; i++) {
   if(char[i] == 
}

C

#include <stdio.h>
#include <ctype.h>
#include <string.h>

int main( void ) {
  char *line;
  fgets(line, 255, stdin);

  size_t line_length = strlen(line);

  for (size_t i = 0; i < line_length; i++) {
    if (isdigit(line[i])) {
      printf("%c\n",line[i]);
    }
  }

  return 0;
}