SOURCE CODE FOR StaticMethods EXAMPLES

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/**
 * Project CountDown1
 * Class Main
 * 
 * The main method invokes the static method
 * countDown.
 */

public class Main
{
    public static void main(String[] args)
    {
        Main.countDown(5);
        
        // Note: since the preceding static
        // method call Main.countDown(5); is
        // within the Main class, this call
        // can be abbreviated as
        //
        // countDown(5);
    }

    private static void countDown(int length)
    {
        int i;
        for(i = length; i >= 0; i--)
        {
            System.out.print(i + "...");
        }
        System.out.println();
        System.out.println("Blastoff!");
    }
}
// Output:
5...4...3...2...1...0...
Blastoff!

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/**
 * Project CountDown2
 * Class Main
 * 
 * The main method invokes the static method
 * countDown. The blastoff message is passed
 * in as well as the number of seconds in the
 * countdown.
 */

public class Main
{
    public static void main(String[] args)
    {
        Main.countDown(5, "Blastoff!");
        
        // Note: since the preceding static
        // method call Main.countDown(5); is
        // within the Main class, this call
        // can be abbreviated as
        //
        // countDown(5);
    }

    private static void countDown(int length, String message)
    {
        int i;
        for(i = length; i >= 0; i--)
        {
            System.out.print(i + "...");
        }
        System.out.println();
        System.out.println(message);
    }
}
// Output:
5...4...3...2...1...0...
Blastoff!

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// Project IWillNot1
// Class Main
    
public class Main
{
    public static void main(String[] args)
    {
        repeatLines();
    }
    
    public static void repeatLines()
    {
        int i;
        for(i = 1; i <= 20; i++)
            System.out.println(i + ". " +
                "I will not talk in class.");
    }
}
// Output:
1. I will not talk in class.
2. I will not talk in class.
3. I will not talk in class.
4. I will not talk in class.
5. I will not talk in class.
6. I will not talk in class.
7. I will not talk in class.
8. I will not talk in class.
9. I will not talk in class.
10. I will not talk in class.
11. I will not talk in class.
12. I will not talk in class.
13. I will not talk in class.
14. I will not talk in class.
15. I will not talk in class.
16. I will not talk in class.
17. I will not talk in class.
18. I will not talk in class.
19. I will not talk in class.
20. I will not talk in class.

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// Project IWillNot2
// Class Main
    
// repeatLines has the parameter line to indicate
// the line to be repeated.
    
public class Main
{
    public static void main(String[] args)
    {
        repeatLines("I will not throw spitballs.");
    }
    
    public static void repeatLines(String line)
    {
        int i;
        for(i = 1; i <= 20; i++)
            System.out.println(i + ". " + line);
    }
}
// Output:
1. I will not throw spitballs.
2. I will not throw spitballs.
3. I will not throw spitballs.
4. I will not throw spitballs.
5. I will not throw spitballs.
6. I will not throw spitballs.
7. I will not throw spitballs.
8. I will not throw spitballs.
9. I will not throw spitballs.
10. I will not throw spitballs.
11. I will not throw spitballs.
12. I will not throw spitballs.
13. I will not throw spitballs.
14. I will not throw spitballs.
15. I will not throw spitballs.
16. I will not throw spitballs.
17. I will not throw spitballs.
18. I will not throw spitballs.
19. I will not throw spitballs.
20. I will not throw spitballs.

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// Project IWillNot3
// Class Main
    
// repeatLines has the parameters line that indicates
// the line to be repeated, and times that indicates
// the number of times to repeat the line.
    
public class Main
{
    public static void main(String[] args)
    {
        repeatLines("I will not throw spitballs.", 15);
    }
    
    public static void repeatLines(String line, 
                                   int times)
    {
        int i;
        for(i = 1; i <= times; i++)
            System.out.println(i + ". " + line);
    }
}
// Output:
1. I will not throw spitballs.
2. I will not throw spitballs.
3. I will not throw spitballs.
4. I will not throw spitballs.
5. I will not throw spitballs.
6. I will not throw spitballs.
7. I will not throw spitballs.
8. I will not throw spitballs.
9. I will not throw spitballs.
10. I will not throw spitballs.
11. I will not throw spitballs.
12. I will not throw spitballs.
13. I will not throw spitballs.
14. I will not throw spitballs.
15. I will not throw spitballs.

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/**
 * Project OldMcDonald
 * Class OldMcDonald
 * 
 * Use static methods to avoid duplicate code.
 */

import javax.swing.JOptionPane;
    
public class OldMcDonald
{
    public static void main(String[] args)
    {
        String animal, sound;
        
        animal = JOptionPane.showInputDialog(
            "Enter an animal.");
        sound = JOptionPane.showInputDialog(
            "Enter an animal sound.");
        printSong(animal, sound);
    }
    
    public static void printSong(
        String theAnimal, String theSound)
    {
        printRefrain();
        System.out.println(
            "And on his farm he had a " + theAnimal + ",");
        printExclamation();
        System.out.println(
            "With a " + theSound + ", " + theSound + " here ");
        System.out.println(
            "And a " + theSound + ", " + theSound + " there.");
        System.out.println(
            "Here a " + theSound + ", there a " + theSound + ",");
        System.out.println(
            "Everywhere a " + theSound + ", " + theSound + ".");
        printRefrain();
    }
    
    public static void printRefrain()
    {
        System.out.println("Old McDonald had a farm,");
        printExclamation();
    }
    
    public static void printExclamation()
    {
        System.out.println("Ee, ay, ee, ay, oh.");
    }
}
// Output:
Old McDonald had a farm,
Ee, ay, ee, ay, oh.
And on his farm he had a cow,
Ee, ay, ee, ay, oh.
With a moo, moo here
And a moo, moo there.
Here a moo, there a moo,
Everywhere a moo, moo.
Old McDonald had a farm,
Ee, ay, ee, ay, oh.

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/**
 * Project Square
 * Class Main
 * 
 * Call the static method square that returns
 * the square of its input. 
 */

public class Main
{
    public static void main(String[] args)
    {     
        int x, y;
        x = 5;
        y = Main.square(x);
        System.out.println(y);
    }
    
    private static int square(int a)
    {
        int b;
        b = a * a;
        return b;
    }
}
// Output:
25

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// Project VowelCount
// Class Main
    
// Write and test the vowelCount method that counts
// the number of vowels in the input string s.
    
public class Main
{
    public static void main(String[] args)
    {
        System.out.println(vowelCount("elephant"));
        System.out.println(vowelCount("tiger"));
        System.out.println(vowelCount("gorilla"));
        System.out.println(vowelCount("bdgt"));
        System.out.println(vowelCount(""));
    }

    public static int vowelCount(String s)
    {
        int i, count = 0;
        char x;
        String u;
        
        u = s.toUpperCase();
        for(i = 0; i < s.length(); i++)
        {
            x = u.charAt(i);
            if(x=='A' || x=='E' || x=='I' || x=='O' || x=='U')
                count++;
        }
        return count;
    }
}
// Output:
3
2
3
0
0

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// Project UpperCaseCount
// Class Main
    
// Write and test the upperCaseCount method that counts
// the number of vowels in the input string s.
    
public class Main
{
    public static void main(String[] args)
    {
        System.out.println(upperCaseCount("This is a test"));
        System.out.println(upperCaseCount("ABCDE"));
        System.out.println(upperCaseCount("abcde"));
        System.out.println(upperCaseCount("12345"));
        System.out.println(upperCaseCount(""));
    }

    public static int upperCaseCount(String s)
    {
        int i, count = 0;
        char x;
       
        for(i = 0; i < s.length(); i++)
        {
            x = s.charAt(i);
            if('A' <= x && x <= 'Z')
                count++;
        }
        return count;
    }
}
// Output:
1
5
0
0
0

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// Project ExistsADigit
// Class Main
    
// Write and test the existsADigit method that returns
// true if there is at least one digit in the 
// input string s.
    
public class Main
{
    public static void main(String[] args)
    {
        System.out.println(existsADigit("bsrct8corsnd"));
        System.out.println(existsADigit("bsrctycorsnd"));
        System.out.println(existsADigit("987654321234"));
        System.out.println(existsADigit(""));
    }

    public static boolean existsADigit(String s)
    {
        int i;
        char x;
        boolean flag = false;
        
        for(i = 0; i < s.length(); i++)
        {
            x = s.charAt(i);
            if('0' <= x && x <= '9')
                flag = true;
        }
        return flag;
    }
}
// Output:
true
false
true
false

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// Project AreAllAsterisks
// Class Main
    
// Write and test the areAllAsterisks method that 
// returns true if all of the characters in the
// string s are asterisks.  Note that true is returned
// for a zero length input string s because each of 
// the characters (namely 0) in s is '*'.
    
public class Main
{
    public static void main(String[] args)
    {
        System.out.println(areAllAsterisks("**********"));
        System.out.println(areAllAsterisks("******&***"));
        System.out.println(areAllAsterisks("*********&"));
        System.out.println(areAllAsterisks(""));
    }

    public static boolean areAllAsterisks(String s)
    {
        int i;
        char x;
        boolean flag = true;
        
        for(i = 0; i < s.length(); i++)
        {
            x = s.charAt(i);
            if(x != '*')
                flag = false;
        }
        return flag;
    }
}
// Output:
true
false
false
true

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// Project ExistsAnX
// Class Main
    
// Write and test the existsAnX method that returns
// true if at least one X or x is in the string,
// false otherwise.
    
public class Main
{
    public static void main(String[] args)
    {
        System.out.println(existsAnX("bsrctxcorsnd"));
        System.out.println(existsAnX("bsrctXcorsnd"));
        System.out.println(existsAnX("bsrctacorsnd"));
        System.out.println(existsAnX(""));
    }

    public static boolean existsAnX(String s)
    {
        int i;
        char x;
        boolean flag = false;
        
        for(i = 0; i < s.length(); i++)
        {
            x = s.charAt(i);
            if(x == 'X' || x == 'x')
                flag = true;
        }
        return flag;
    }
}
// Output:
true
true
false
false

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// Project FirstAndLastAreEqual
// Class Main
    
// Write and test the firstAndLastAreEqual method that 
// Return true if the first and last character of the
// input string s.  Return false if s.length() == 0.
    
public class Main
{
    public static void main(String[] args)
    {
        System.out.println(firstAndLastAreEqual("elephant"));
        System.out.println(firstAndLastAreEqual("pop"));
        System.out.println(firstAndLastAreEqual("a"));
        System.out.println(firstAndLastAreEqual(""));
    }

    public static boolean firstAndLastAreEqual(String s)
    {
        int i;
        char first, last;
        
        if (s.length() == 0)
            return false;
        else
        {
            first = s.charAt(0);
            last = s.charAt(s.length() - 1);
            return first == last;
        }
    }
}
// Output:
false
true
true
false

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