How to Swap rows?

Question

I am given int[][] Science, int rowOne and int rowTwo. How can I swap rowOne and rowTwo?

I know that I am supposed to hold one row in temp variable, but I do not understand how it works. How does temp work?

Possible duplicate of [How to write a basic swap function in Java](http://stackoverflow.com/questions/3624525/how-to-write-a-basic-swap-function-in-java) — azurefrog, Jan 10 '16 at 04:40
@Mlaura Isn't what Matthew Huie shows being the solution of what you need? What else are you asking for? — user3437460, Jan 10 '16 at 09:12

score 1 · Accepted Answer · answered Jan 10 '16 at 13:02

Consider you have

rowOne =2;
rowTwo =3;

Now think without third variable:

if you want to swap them you need to assign one of them to other like:

rowOne=rowTwo;

But if we do so , now rowOne is 3 , but previously it was 2. You need to remember that value and hence we need to store it in temporary memory . That's our third variable. That's how it works.

temp=rowOne ; //This third variable helps to remember the value.
rowOne=rowTwo;
rowTwo=temp;

score 0 · Answer 2 · edited Jan 10 '16 at 06:29

Assuming that int[][] Science has 2 rows and that you would like to swap the order of these two rows, you could do the following in Java:

int tempRow[] = Science[0];
Science[0] = Science[1];
Science[1] = tempRow;

I'm not exactly sure what you meant by rowOne and rowTwo in your question, but you can use a temporary int[] to hold one of the rows, while performing the swap. This works as Java has references to each row in the two-dimensional array.

How to Swap rows?

2 Answers2