complete the method named countdown (method stub provided) so that it accepts an int countFrom as its parameter and prints each number from countFrom to 1 on a single line separated by a space. This method should not return anything (void return type).
Hint: Use a loop and think
about the starting value you want to print, the ending value that will
print, and how you want to update the value between iterations.
Example: countdown(5) should print:
5 4 3 2 1 Example2: countdown(-1) should not print anything. Example3:
countdown(9) should print: 9 8 7 6 5 4 3 2 1
Ensure you are thoroughly calling
and testing your methods before submitting to zyBooks.
Problem 2 - Arrays as Parameters
Complete the curve method
(method stub provided for you) so that it loops through the int[] grades,
incrementing each non-zero grade by 2. Grades of 0 should not be changed.
This method should not print or return anything, but should modify the
contents of the grades array.
Hint - you can test that your method
works in main by printing the values in grades both before and after this
method is called.
Example: Passing in an int[]
containing: {95, 80} should modify the array to {97,82} Example2: Passing in a
int[] containing: {70, 0, 99} should modify the array to {72, 0, 101}
Problem 3 - Returning Arrays, Arrays
as Parameters, String methods
Write a method named acronyms
that accepts an array of type String as its parameter and returns an
array of type char. This method stub is not provided for you. Method
name, return type, and parameter(s) should match exactly to receive
credit. You should not use the keyword static in the method header.
Your method should create a
new char array the same size as the String array passed in. You should
then use a loop to populate the char array with the first letter of each
individual String stored in the array.
Hint - the charAt method in the
String class retrieves a single char from a specified index.
Example: Passing in an
String[] containing: {"tiger", "king"} should return a
char[] of size 2 containing {'t', 'k'} Example2: Passing in an String[]
containing: {"go dawgs", "uga", "java"} should
return a char[] of size 3 containing {'g', 'u', 'j'}
Problem 4 - Scanner in methods,
String methods, Algorithm design, Return Statements
Write a method named
setPassword that accepts a Scanner object as its parameter and returns a
boolean. This method stub is not provided for you. Method name, return
type, and parameter(s) should match exactly to receive credit. You should
not use the keyword static in the method header.
Your method should read in a
String password using the nextLine method and the the Scanner object
passed in as the method parameter. Your method should then return either
true or false depending on if all criteria of a password is met.
A valid password (returning true)
would have the following criteria:
- The password contains at least 8 characters
- The password contains at least 1 capital letter/char
- The password contains at least 1 lowercase letter/char
If ALL of the above conditions
are met, your method should return true. If any of the above conditions
are NOT met, your method should return false.
Example: a user input of
"Coding99" or "Java12345" would return true Example2: a
user input of "Java123" would return false //only 7 characters
Example3: a user input of "JAVA12345" would return false //no
lowercase Example4: a user input of "java12345" would return false
//no uppercase
Answer
import java.util.Scanner; //imported
for you!
public class Exam2
{
//Problem 1
public void countdown(int
countFrom)
{
//YOUR
CODE HERE
if(
countFrom < 1 )
{
}else{
for(int i = countFrom ; i > 0 ;
i--){
System.out.print( i+" " );
}
System.out.println("");
}
}
//Problem 2
public void curve(int[] grades)
{
//YOUR
CODE HERE
for(int i
= 0 ; i < grades.length ; i++){
if( grades[i] != 0 ){
grades[i] = grades[i] + 2;
}
}
}
//Problem 3
//method stub not provided - YOUR
CODE HERE
public char[] acronyms (String [] str){
char[] firstletters = new
char[str.length] ;
for(int
i = 0 ; i < str.length ; i++)
firstletters[i]
= str[i].charAt(0);
return firstletters;
}
//Problem 4
//method stub not provided - YOUR
CODE HERE
public boolean setPassword (Scanner
input ){
boolean length =false, lower =false,
upper=false ;
System.out.print("Enter a
password: ");
String password = input.nextLine();
if( password.length() >= 8 )
length
= true;
for (int i = 0; i <
password.length() - 1; i++) {
if (
Character.isLowerCase(password.charAt(i))){
lower
= true ;
break;
}
}
for (int i = 0; i < password.length()
- 1; i++) {
if (
Character.isUpperCase(password.charAt(i))){
upper
= true ;
break;
}
}
return (upper &&lower&&
length);
}
}
import java.util.*; //All items in
java.util package (Scanner, ArrayList, HashSet, etc.) imported for you
import java.util.Arrays;
public class Main
{
public static void main(String[] args)
{
//You
can test your code here.
//This
file is not graded.
// instance object classs from Exam2
Exam2 examtest = new Exam2();
// test countdown method
examtest.countdown(9);
int h [] = {95,0, 80} ;
System.out.println( "Before
calling curve method : "+Arrays.toString(h));
examtest.curve(h);
System.out.println( "After calling
curve method : "+Arrays.toString(h));
String[] str = {"go
dawgs", "uga", "java"} ;
System.out.println( "After calling
acronyms method : "+Arrays.toString(examtest.acronyms(str)));
System.out.println( "After calling
setPassword method : "+examtest.setPassword(new Scanner(System.in))
);
}
}