public class EckMethods
{
  public static void main(String[] args)
  {

    int x = 7, y = 45;
    String s = "yes";
    String s2 = "abcdefg";
    String s3 = "It will be cold out today.";

    printSum(x, y);
    printDifference(x, y);
    printProduct(x, y);
    printQuotient(x, y);
    printMod(x, y);

    printFirstCharacter(s);
    printContains(s2);
    printStringReplace(s3);
  }
    // A call to a method that prints the sum of x and y
    public static void printSum(int num1, int num2){
      int sum;
      sum = num1 + num2;

      System.out.println(sum);
    }

    // A call to a method that prints the difference of x and y
    public static void printDifference(int num1, int num2){
      int dif;
      dif = num1 - num2;

      System.out.println(dif);
    }

    // A call to a method that prints the product of x and y
    public static void printProduct(int num1, int num2){
      int prod;
      prod = num1 * num2;

      System.out.println(prod);
    }

    // A call to a method that prints the quotient of x and y
    // Make sure to test whether the divisor is 0 - we don't want run time errors!
    public static void printQuotient(int num1, int num2){
       int quo;
       quo = num1 / num2;

       if (num2 == 0){
         System.out.println(" Divisor is 0. Exiting. ");
         System.exit(0);
       }else
         System.out.println(quo);
    }

    // A call to a method that prints result of x modulus y
    public static void printMod(int num1, int num2){
       int mod;
       mod = num1 % num2;

       System.out.println(mod);
    }

    // A call to a method that prints the first character of a string
    public static void printFirstCharacter(String str){

      System.out.println(str.charAt(0));
    }

    // A call to a method that prints whether the string contains the letter n
    // You can use the string method indexOf or contains
    public static void printContains(String str){

      System.out.println(str.contains("n"));
    }

    // A call to a method that replaces one string with another
    // You can use the string method replace
    public static void printStringReplace(String str){

      System.out.println(str.replace("cold", "warm"));
    }
  }