C PROGRAMMING PROGRAM • FUNCTIONS, PREPROCESSOR & COMMAND LINE

Demonstrate Call by Value

Learn how to demonstrate call by value using a clear C program.

BeginnerFunctionsValue parametersLocal copies

PROBLEM UNDERSTANDING

Input and expected output

Sample input

No input required

Sample output

Inside function: 20 10
After call: 10 20

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

void swap_copies(int first, int second)
{
    int temporary = first;
    first = second;
    second = temporary;
    printf("Inside function: %d %d\n", first, second);
}

int main(void)
{
    int first = 10, second = 20;
    swap_copies(first, second);
    printf("After call: %d %d\n", first, second);
    return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

Inside function: 20 10
After call: 10 20

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Pass copies into the function and observe that changing them does not change the caller's variables.
Display the computed result.

Pass copies into the function and observe that changing them does not change the caller's variables.

EFFICIENCY

Time and space complexity

Time complexity

O(1)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

Check this

Use the correct format specifier for every variable.

Check this

Initialize variables before using their values.

Check this

Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.