Question

Need help with java project please!!

Answer 1

I might be able to help

Answer 2

have u worked with java before?

Answer 3

yes I have

Answer 4

okay, awesome!

Answer 5

so i've basically completed the program except for the last step

Answer 6

those are the instructions

Answer 7

need help with the second step

Answer 8

hmm can i get the pictures

Answer 9

what pictures?

Answer 10

modify the main method so after the call to the swap method the actual values of num1 and num2 are swapped in main and show this in the output. Your output will have one additional line after the listing on page 213 that shows the values of the two numbers in main after they are swapped. See new output line below in blue text.
Before invoking the swap method, num1 is 1 and num2 is 2
Inside the swap method
Before swapping n1 is 1 n2 is 2
After swapping n1 is 2 n2 is 1
After invoking the swap method, num1 is 1 and num2 is 2
After swapping the numbers in main method, num1 is 2 and num2 is 1.

Answer 11

*Listings

Answer 12

thats the step i need help with

Answer 13

public class Chpt6_Tutorial {

public static void main(String[] args) {
// Declare and initialize variables
int num1 = 1;
int num2 = 2;

System.out.println("Before invoking the swap method, num1 is " + num1 + " and num2 is " + num2);

// Invoke the swap method to attempt to swap two variables
swap(num1, num2);

System.out.println("After invoking the swap method, num1 is " + num1 + " and num2 is " + num2);

}

/** Swap two variables */
public static void swap(int n1, int n2){
System.out.println("\tInside the swap method");
System.out.println("\t\tBefore swapping, n1 is " + n1 + " and n2 is " + n2);

//Swap n1 with n2
int temp = n1;
n1 = n2;
n2 = temp;

System.out.println("\t\tAfter swapping, n1 is " + n1 + " and n2 is " + n2);

}

}

Answer 14

thats my code

Answer 15

hmmm not sure ive only done really basic things i might know someone who can help

Answer 16

Wait, so you really just need to swap the values of 2 variables right?

Answer 17

okay,thanks anyway

Answer 18

yes

Answer 19

Don't you have it here:

//Swap n1 with n2
int temp = n1;
n1 = n2;
n2 = temp;


You stored n1 into a temporary location.
Then made n1 = n2
Then used n2 = the temporary location.

Answer 20

yes, but then it says

Answer 21

modify the main method so after the call to the swap method the actual values of num1 and num2 are swapped in main and show this in the output. Your output will have one additional line after the listing on page 213 that shows the values of the two numbers in main after they are swapped. See new output line below in blue text.
Before invoking the swap method, num1 is 1 and num2 is 2
Inside the swap method
Before swapping n1 is 1 n2 is 2
After swapping n1 is 2 n2 is 1
After invoking the swap method, num1 is 1 and num2 is 2
After swapping the numbers in main method, num1 is 2 and num2 is 1.

Answer 22

no

Answer 23

So you just need to transfer the swapping into the main() instead of swap() right?

Answer 24

im not sure, thats why i came for help haha, not really clear on what i need to do. sorry haha

Answer 25

what happens when you run it

Answer 26

@yumi
Have you learned about call by reference and call by value?
Java passes every everything by value.
So if you call swap(a,b), in the method, you're just swapping copies of a and b.
Is that where you have a problem?