Q: If y is 7 and z is 3, what is the result of the expression y += z using the compound assignment operator in Java?  

In Java, the expression y += z is a compound assignment operator, which adds the value of z to the current value of y and assigns the result back to y. It is equivalent to the expression y = y + z.

If y is initially 7 and z is 3, the result of the expression y += z would be:

y = y + z;

After the operation, the value of y will be 10 (7 + 3).

Here's an example in Java:

public class CompoundAssignmentExample {
    public static void main(String[] args) {
        // Declare variables
        int y = 7;
        int z = 3;

        // Compound assignment
        y += z;

        // Display the result
        System.out.println("The value of y after y += z is: " + y);
    }
}

When you run this Java program, it will output "The value of y after y += z is: 10".