JAVA QUIZ package popQ; public class Methods { /* 1. Write a complete Java metho
ID: 3771634 • Letter: J
Question
JAVA QUIZ
package popQ;
public class Methods {
/*
1. Write a complete Java method called sumNums that takes no parameters and returns an integer.
The method uses a do-while loop to ask the user to enter a series of positive integer values and keeps a running total.
Use a sentinel (-1) to allow the user to indicate when they are finished.
The method returns the total.
*/
// Write your method here
/*
2. Write a complete Java method called checkPassword that takes a String as
a parameter (password) and returns a boolean. First, check that the password is
at least 8 characters long. Then use a while loop to check that the
password contains at least one digit. If the password has the correct length
and contains a digit, return true, otherwise return false
*/
// Write your method here
/*
3. Write a complete Java method called authenticate that takes two Strings (username, password)
as parameters and returns a boolean. If the username parameter has the value "Chucky" and
the password parameter has the value "Cheese1", return true. Otherwise return false.
*/
// Write your method here
/*
4. Write a complete Java method called getScoreSheet that takes two ints
as parameters (rows and columns) and constructs a 2-dimensional array
of doubles (calles scores) with a size based on the rows and columns parameters.
Use a nested loop to initialize each value in the array to 100.00.
The method returns the scores array.
*/
// Write your method here
/*
5. Write a complete Java method called writeList that takes an ArrayList of Strings as a parameter
and writes each String as a line in a text file.
Make sure to handle the Exception that might be thrown and print the error message to the
command line.
*/
// Write your method here
}
Explanation / Answer
Implemented parts 1,2,3 and 4
package assignment;
import java.util.Scanner;
public class Methods {
public static void main(String args[]) {
Methods methods = new Methods();
System.out.println("Testing sum function");
int sum = methods.sumNums();
System.out.println(" Sum of numbers : "+sum);
System.out.println("Testing checkPassword");
System.out.println(" Password: P@ssw@rd : "+methods.checkPassword("P@ssw@rd"));
System.out.println(" Password: P@s1 : "+methods.checkPassword("P@s1"));
System.out.println(" Password: P@s1abcedf : "+methods.checkPassword("P@s1abcedf"));
System.out.println("Testing authenticate");
System.out.println(" Username: John, Password: Chunky "+methods.authenticate("John", "Chunky"));
System.out.println(" Username: Chucky, Password: Cheese1 "+methods.authenticate("Chucky", "Cheese1"));
System.out.println("Testing getScoreSheet");
double scores[][] = methods.getScoreSheet(5, 4);
}
public Methods() {
}
/*
1. Write a complete Java method called sumNums that takes no parameters and returns an integer.
The method uses a do-while loop to ask the user to enter a series of positive integer values and keeps a running total.
Use a sentinel (-1) to allow the user to indicate when they are finished.
The method returns the total.
*/
// Write your method here
public int sumNums() {
int total = 0;
int input = 0;
Scanner scan = new Scanner(System.in);
do {
System.out.println("Enter a positive integer ( Negative value(-1 or other) to quit): ");
input = scan.nextInt();
if(input >= 0)
total += input;
} while(input >= 0);
return total;
}
/*
2. Write a complete Java method called checkPassword that takes a String as
a parameter (password) and returns a boolean. First, check that the password is
at least 8 characters long. Then use a while loop to check that the
password contains at least one digit. If the password has the correct length
and contains a digit, return true, otherwise return false
*/
// Write your method here
public boolean checkPassword(String password) {
if(password != null && password.length() >= 8) {
int i = 0;
while(i < password.length()) {
if(Character.isDigit(password.charAt(i)))
return true;
i++;
}
}
return false;
}
/*
3. Write a complete Java method called authenticate that takes two Strings (username, password)
as parameters and returns a boolean. If the username parameter has the value "Chucky" and
the password parameter has the value "Cheese1", return true. Otherwise return false.
*/
// Write your method here
public boolean authenticate(String username, String password) {
if("Chucky".equals(username) && "Cheese1".equals(password) )
return true;
return false;
}
/*
4. Write a complete Java method called getScoreSheet that takes two ints
as parameters (rows and columns) and constructs a 2-dimensional array
of doubles (calles scores) with a size based on the rows and columns parameters.
Use a nested loop to initialize each value in the array to 100.00.
The method returns the scores array.
*/
// Write your method here
public double[][] getScoreSheet(int rows, int columns) {
if(rows <= 0 || columns <= 0)
return null;
double[][] scores = new double[rows][columns];
for(int i= 0; i < rows; i++)
for(int j = 0; j < columns; j++)
scores[i][j] = 100.0;
return scores;
}
}
--output--
Testing sum function
Enter a positive integer ( Negative value(-1 or other) to quit):
10
Enter a positive integer ( Negative value(-1 or other) to quit):
20
Enter a positive integer ( Negative value(-1 or other) to quit):
-1
Sum of numbers : 30
Testing checkPassword
Password: P@ssw@rd : false
Password: P@s1 : false
Password: P@s1abcedf : true
Testing authenticate
Username: John, Password: Chunky false
Username: Chucky, Password: Cheese1 true
Testing getScoreSheet
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