1. TA: Nouf Al-Harbi NoufNaief.net ::: nouf200@hotmail.com
Programming 2 LAB
TA: Nouf Al-Harbi
NoufNaief.net :::

2. The String Class Applications
Lab 2
The String Class Applications

3. Program
Phone keypads

4. Phone keypads Problem Description:
The international standard letter/number mapping found on the telephone is shown below:
Phone keypads

5. public static int getNumber(char uppercaseLetter)
Write a method that returns a number, given an uppercase letter, as follows:
public static int getNumber(char uppercaseLetter)
Write a test program that prompts the user to enter a phone number as a string. The input number may contain letters. The program translates a letter (upper- or lowercase) to a digit and leaves all other characters intact.
Phone keypads

6. Phone keypads <Output> Enter a string: 1-800-Flowers
<End Output>
Enter a string: 1800flowers
Phone keypads

7. Solution..

8. import java.util.Scanner; public class Exercise9_7 { public static void main(String[] args) { Scanner input = new Scanner(System.in); // Prompt the user to enter a string System.out.print("Enter a string: "); String s = input.nextLine(); for (int i = 0; i < s.length(); i++) { if (Character.isLetter(s.charAt(i))) System.out.print(getNumber(Character.toUpperCase(s.charAt(i)))); else System.out.print(s.charAt(i)); }

9. public static int getNumber(char uppercaseLetter) { int number = 0; switch (uppercaseLetter) case 'A': case 'B': case 'C': number = 2; break; case 'D': case 'E': case 'F': number = 3; break; case 'G': case 'H': case 'I': number = 4; break; case 'J': case 'K': case 'L': number = 5; break;
case 'M':
case 'N':
case 'O': number = 6; break;
case 'P':
case 'Q':
case 'R':
case 'S': number = 7; break;
case 'T':
case 'U':
case 'V': number = 8; break;
case 'W':
case 'X':
case 'Y':
case 'Z': number = 9; break; }
return number;

10. Program
Checking Password

11. Checking Password Problem Description :
Some Websites impose certain rules for passwords. Write a method that checks whether a string is a valid password. Suppose the password rule is as follows:
A password must have at least eight characters.
A password consists of only letters and digits.
A password must contain at least two digits.
Write a program that prompts the user to enter a password and displays "valid password" if the rule is followed or "invalid password" otherwise.
Checking Password

12. Checking Password Sample 1 Sample 2
Enter a string for password: wewew43x
valid password
Sample 2
Enter a string for password: 343a
invalid password
Checking Password

13. Solution..

14. public class Test { public static void main(String[] args) { // Prompt the user to enter a password java.util.Scanner input = new java.util.Scanner(System.in); System.out.print("Enter a string for password: "); String s = input.nextLine(); if (isValidPassword(s)) { System.out.println("Valid password"); } else { System.out.println("Invalid password");

15. // Count the number of digits int count = 0;
/** Check if a string is a valid password */ public static boolean isValidPassword(String s) { // Only letters and digits? for (int i = 0; i < s.length(); i++) { if (!Character.isLetter(s.charAt(i)) && !Character.isDigit(s.charAt(i))) return false; } // Check length if (s.length() < 8)
// Count the number of digits
int count = 0;
for (int i = 0; i < s.length(); i++) {
if (Character.isDigit(s.charAt(i)))
count++; }
if (count >= 2)
return true;
else
return false;

16. End of Lab 2