This Java program defines a class `Swap`, with two methods:...

This Java program defines a class Swap, with two methods: swap (a static method) and main. Here's a line-by-line explanation of what the code does:

1. swap(int a, int b) method:

   • This method takes two integer parameters, a and b.
   • It uses a temporary variable tmp to swap the values of a and b.
     • The value of a is stored in tmp, then b's value is assigned to a, and finally, tmp is assigned to b.

   Key Limitation:

   • This swapping only affects the local copies of a and b, which were passed to the method. Java is pass-by-value, so the original variables in the calling method (main) do not change.

2. main method:

   • This is the program's entry point.
   • Two integers are defined: a = 3 and b = 7.
   • The swap method is called with these two integers (a and b) as arguments.
   • After the swap method call, the program prints a and b.

3. Behavior:

   • When swap(a, b) is called, a and b are passed by value (i.e., their copies are passed to the method).
   • The swap method performs the swap operation but only on its local copies. The original variables in main remain unchanged.
   • This means the program will output the original values of a and b.

4. Output:

   3
   7
   

   Even though swap(a, b) is called, it has no effect on the variables a and b in main because the swap happens only on the method's local copies.

Conclusion: This program tries to swap two integers using a method, but the swapping does not affect the original variables outside the method due to Java's pass-by-value nature.