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

The String Class Applications Lab 2 The String Class Applications

Program Phone keypads

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

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

Phone keypads <Output> Enter a string: 1-800-Flowers 1-800-3569377 <End Output> Enter a string: 1800flowers 18003569377 Phone keypads

Solution..

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)); }

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;

Program Checking Password

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

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

Solution..

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");

// 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;

End of Lab 2