recursion theory in java code example

Example 1: recursion in java

class scratch{
    public static long factorial(int n){
        if ( n == 1 ){
            return 1;
        }
        else{
            return n * factorial( n - 1 );
        }
    }
    public static void main(String[] args) {
        System.out.println( factorial(5) );
        //Print 120 (5!) to the console
    }
}

Example 2: java recursion

public void removeDigits(String string) {
  if(string.length == 1) {
    if(Character.isDigit(string.CharAt(0))) {
      return "";
    } else {
      return string;
    }
  } else {
    if(Character.isDigit(string.CharAt(0))) {
      return removeDigits(string.substring(1));
    } else {
      return string.substring(0, 1) + removeDigits(string.substring(1));

public static void main(String[] args) {
  String string = "1a2b3c"
  System.out.println(removeDigits(string)); //will print "abc"
}