Question

Write a function whose prototype is void exchange (int \(* p, \text { int } \star q)\) that takes two pointers to integer variables and exchanges the values in those variables.

Short answer

Question: Write a function that takes two pointers to integers as input and exchanges the values in those variables. Answer: To write a function that takes two pointers to integers as input and exchanges the values, you can create a temporary integer variable to store the value of the first integer variable and then assign the value of the second integer variable to the first integer variable. Finally, assign the temporary variable's value to the second integer variable. The function would look like: ```c void exchange(int *p, int *q) { int temp = *p; *p = *q; *q = temp; } ``` To test the function, you can call the exchange function with two integer variables' addresses as arguments and print the values of the variables before and after exchanging them.

Step-by-step solution

Understanding the function prototype

The function prototype given is 'void exchange(int *p, int *q)'. This means that the function takes two pointers to integers as input and doesn't return any value (void return type). The function's main task is to exchange the values of the two integer variables that the pointers are pointing to.

Write the function

To write the function, first create a temporary integer variable to store the value of the first integer variable (*p). Then, assign the value of the second integer variable (*q) to the first integer variable (*p). Finally, assign the temporary variable's value to the second integer variable (*q). The function looks like this: void exchange(int *p, int *q) { int temp = *p; // Store the value of the first integer variable *p = *q; // Assign the value of the second integer variable to the first integer variable *q = temp; // Assign the temporary variable's value to the second integer variable }

Test the function

To test the function, create a main function that calls the exchange function with two integer variables' addresses as arguments. Then, print the values of the variables before and after exchanging them to see if the function works as expected. #include void exchange(int *p, int *q); int main() { int a = 10; int b = 20; printf("Before exchange:\na = %d, b = %d\n", a, b); // Output: a = 10, b = 20 exchange(&a, &b); // Call the exchange function with addresses of a and b printf("After exchange:\na = %d, b = %d\n", a, b); // Output: a = 20, b = 10 return 0; }