CS110 Programming Language I Lab 9: Methods II Computer Science Department Spring 2014 By: TA. Nora Alaqeel

( Variables Scope ) Find Errors (If Any): class ScopeEx { public static void main(String args[]) { int num = 1; { // creates a new scope int num = 2; } } //end main } //end class By: TA. Nora Alaqeel

( Variables Scope ) Find Errors (If Any): class ScopeEx { public static void main(String args[]) { { // creates a new scope int num = 1; } int num = 2; } //end main } //end class By: TA. Nora Alaqeel

( Variables Scope ) Find Errors(If Any): class ScopeEx { public static void main(String args[]) { int n1; n1 = 10; if(n1 == 10) { // start new scope int n2 = 20; System.out.println("n1 and n2 : "+ n1 +" "+ n2); } System.out.println("n1 is " + n1); System.out.println(”n2 is " + n2); By: TA. Nora Alaqeel

( Method Overloading ) (T or F) Tell whether the following method overloading is true or false: Public static void myMethod (int firstArg, int secondArg) { ….. } Public static void myMethod (char firstArg, int secondArg) By: TA. Nora Alaqeel

( Method Overloading ) (T or F) Tell whether the following method overloading is true or false: Public static void myMethod (int firstArg, int secondArg) { ….. } Public static void myMethod (int firstArg) By: TA. Nora Alaqeel

( Method Overloading ) (T or F) Tell whether the following method overloading is true or false: Public static void myMethod (int firstArg, double secondArg) { ….. } Public static void myMethod (double firstArg, int secondArg) By: TA. Nora Alaqeel

( Method Overloading ) (T or F) Tell whether the following method overloading is true or false: Public static void myMethod (int firstArg, int secondArg) { ….. } Public static void myMethod (int first, int second) By: TA. Nora Alaqeel

( Method Overloading ) (T or F) Tell whether the following method overloading is true or false: Public static void myMethod (int firstArg, int secondArg) { ….. } Public static String myMethod (int firstArg, int secondArg) By: TA. Nora Alaqeel

Problem Description Sample Outputs: ( Returning Values + Calling ) Problem Description (Room Type) Write a program with a method named computeRoomArea which takes two float arguments entered by the user, as the length and width of a room. The method must calculate and returns the area of the room. In the main() method, you should display the result, and one of the following statements: This is a Huge Room. (If the room’s area larger than 100) This is a Tiny Room. (Otherwise – If smaller or equal to 100)   Hint: Area= length * width Sample Outputs: Please Enter length and width of the room: 12 10 The Area of the Room= 120 This is a Huge Room. By: TA. Nora Alaqeel

Code Skelton import java.util.Scanner; public class Room { public static void main(String[] args) { Scanner input = new Scanner(System.in); float length, width, area; System.out.print( "Please Enter length and width of the room: ") ; length = input.nextFloat(); width = input.nextFloat(); area = computeRoomArea(length, width); System.out.println( "The Area of the Room = " + area ); if (area > 100) System.out.println( "This is a Huge Room." ); else System.out.println( “This is a Tiny Room." ); } //end main   By: TA. Nora Alaqeel

Code Skelton Cont. public static float computeRoomArea(float l , float w) { return (l * w); } //end computeRoomArea } // end class By: TA. Nora Alaqeel

Evaluation (Print Grade) Write a program with a method named printGrade which takes one float argument entered by the user, as the user’s score. The method must returns the grade of the student. In the main() method, you should print the grade. The method header should be as the following: public static char printGrade(double score) Grade Score A Score >= 90.0 B 90.0 > Score >= 80.0 C 80.0 > Score >= 70.0 D 70.0 > Score >= 60.0 F Score < 60.0 By: TA. Nora Alaqeel

Sample Output: Please Enter Your Score: 87 Your Grade Is: B By: TA. Nora Alaqeel

Q1: Write a method named lastDigit that returns the last digit of an integer. For example, lastDigit(3572) should return 2. It should work for negative numbers as well. For example, lastDigit(-947) should return -7. Write a program to test your method.

 Q2: Write a program containing a method named countChars that receives a string read from the user, and count the number of characters in this string. Print out the result on main method.  

  Q3: Write a method named swapPairs that accepts a String as a parameter and returns that String with each pair of adjacent letters reversed. If the String has an odd number of letters, the last letter is unchanged. For example, the call swapPairs("forget") should return "ofgrte" and the call swapPairs("hello there") should return "ehll ohtree". Write a program to test your method.