Question

7.2.3: Printing array elements with a for loop.

Write a for loop to print all elements in courseGrades, following each element with a space (including the last). Print forwards, then backwards. End each loop with a newline. Ex: If courseGrades = {7, 9, 11, 10}, print:

7 9 11 10 
10 11 9 7 

Hint: Use two for loops. Second loop starts with i = courseGrades.length - 1. (Notes)

Also note: If the submitted code tries to access an invalid array element, such as courseGrades[9] for a 4-element array, the test may generate strange results. Or the test may crash and report "Program end never reached", in which case the system doesn't print the test case that caused the reported message.

import java.util.Scanner;

public class CourseGradePrinter {
public static void main (String [] args) {
Scanner scnr = new Scanner(System.in);
final int NUM_VALS = 4;
int [] courseGrades = new int[NUM_VALS];
int i;

for (i = 0; i < courseGrades.length; ++i) {
courseGrades[i] = scnr.nextInt();
}

/* Your solution goes here */

}
}

Answer 1

import java.util.Scanner;

public class CourseGradePrinter {
    public static void main(String[] args) {
        Scanner scnr = new Scanner(System.in);
        final int NUM_VALS = 4;
        int[] courseGrades = new int[NUM_VALS];
        int i;

        for (i = 0; i < NUM_VALS; i++) {
            courseGrades[i] = scnr.nextInt();
        }

        for (i = 0; i < NUM_VALS; i++) {
            System.out.print(courseGrades[i] + " ");
        }
        System.out.println();

        for (i = NUM_VALS - 1; i >= 0; i--) {
            System.out.print(courseGrades[i] + " ");
        }
        System.out.println();
    }
}