Merge pull request #7 from code-for-tomorrow/ch11-rebecca

Add Ch. 11 example code

Author: phrdang

src/com/codefortomorrow/intermediate/chapter11/examples/JavaDocs.java

@@ -0,0 +1,13 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+public class JavaDocs {
+    /**
+     * Returns the average of two doubles
+     * @param a  first double
+     * @param b  second double
+     * @return the average of two doubles
+     */
+    public static double average(double a, double b) {
+        return (a + b) / 2;
+    }
+}

src/com/codefortomorrow/intermediate/chapter11/examples/MethodCalls.java

@@ -0,0 +1,11 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+public class MethodCalls {
+    public static void main(String[] args) {
+        sum(5, 4);
+    }
+
+    public static void sum(int a, int b) {
+        System.out.println(a + b);
+    }   
+}

src/com/codefortomorrow/intermediate/chapter11/examples/Methods.java

@@ -2,11 +2,13 @@
 
 public class Methods {
     public static void main(String[] args) {
+        // prints "Hello World" 5 times
         for (int i = 0; i < 5; i++) {
             printMessage();
         }
     }
 
+    /** Prints "Hello World" */
     public static void printMessage() {
         System.out.println("Hello World");
     }

src/com/codefortomorrow/intermediate/chapter11/examples/Overloading.java

@@ -0,0 +1,19 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+public class Overloading {
+    public static void main(String[] args) {
+        // call 2-arg sum
+        System.out.println(sum(2, 3)); // prints 5
+
+        // call 3-arg sum
+        System.out.println(sum(1, 4, 7)); // prints 12
+    }
+
+    public static int sum(int a, int b) {
+        return a + b;
+    }
+
+    public static int sum(int a, int b, int c) {
+        return sum(a, b) + c;
+    }
+}

src/com/codefortomorrow/intermediate/chapter11/examples/Parameters.java

@@ -0,0 +1,28 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+public class Parameters {
+    public static void main(String[] args) {
+        // scoopIceCream with 1 parameter
+        scoopIceCream("chocolate");
+        scoopIceCream("vanilla");
+        scoopIceCream("strawberry");
+
+        // scoopIceCream with multiple parameters
+        scoopIceCream("chocolate", true);
+        scoopIceCream("vanilla", false);
+        scoopIceCream("strawberry", true);
+    }
+
+    public static void scoopIceCream(String flavor) {
+        System.out.println("Here's a scoop of " + flavor + " ice cream!");
+    }
+
+    public static void scoopIceCream(String flavor, boolean wantCone) {
+        if (wantCone) {
+            System.out.println("Here's a scoop of " + flavor + 
+                " ice cream on a cone!");
+        } else {
+            System.out.println("Here's a scoop of " + flavor + " ice cream!");
+        }
+    }
+}

src/com/codefortomorrow/intermediate/chapter11/examples/ReturnTypes.java

@@ -0,0 +1,17 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+public class ReturnTypes {
+    public static void main(String[] args) {
+        printSum(5, 4);
+        int myNumber = sum(5, 4) / 2;
+        System.out.println(myNumber);
+    }
+
+    public static void printSum(int a, int b) {
+        System.out.println(a + b);
+    }
+
+    public static int sum(int a, int b) {
+        return a + b;
+    }
+}

src/com/codefortomorrow/intermediate/chapter11/examples/VariableScope.java

@@ -0,0 +1,20 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+public class VariableScope {
+    public static void main(String[] args) {
+        method1(); // prints 5.0
+        method2(); // prints 2.0
+        // System.out.println(a);  throws an exception
+    }
+
+    public static void method1() {
+        double a = 5;
+        System.out.println(a);
+    }
+
+    public static void method2() {
+        // both variables are called a
+        double a = 2;
+        System.out.println(a);
+    }
+}

src/com/codefortomorrow/intermediate/chapter11/examples/WhyMethods.java

@@ -0,0 +1,36 @@
+package com.codefortomorrow.intermediate.chapter11.examples;
+
+import java.util.Scanner;
+
+public class WhyMethods {
+    public static void main(String[] args) {
+        // cleaner code because methods group actions
+        printMessages();
+        printSum();
+    }
+
+    /** Prints 3 messages */
+    public static void printMessages() {
+        System.out.println("May the Force be with you");
+        System.out.println("Tahiti, it's a magical place");
+        System.out.println("Live long and prosper");
+    }
+
+    /** Prints the sum of 2 numbers */
+    public static void printSum() {
+        Scanner input = new Scanner(System.in);
+
+        // prompt user to enter 2 numbers
+        System.out.print("Enter number 1: ");
+        double num1 = input.nextDouble();
+        System.out.print("Enter number 2: ");
+        double num2 = input.nextDouble();
+
+        double sum = num1 + num2;
+
+        // print the sum of those numbers
+        System.out.println("Sum: " + sum);
+
+        input.close();
+    }
+}