Swap two numbers using command line

Write a program to swap two numbers using command line argument

//definition of main in command-line arguments

int main(int argc, char *argv[])

{

  //some coding

} 

1. argc – It is known as argument count, it stores the count of the number of arguments.
2. argv[] – Pointer, contains location of all the values(arguments).
3. *argv[] – Array of values of all the arguments

Approach

C

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
    if (argc != 3)
    {
        printf("Enter two numbers ");
        return -1;
    }
    else
    {
        int firstNum = atoi(argv[1]);
        int secondNum = atoi(argv[2]);
        printf("Numbers before swap:\n");
        printf("First = %d, Second = %d\n", firstNum, secondNum);
        int temp = firstNum;
        firstNum = secondNum;
        secondNum = temp;
        printf("Numbers after swap:\n");
        printf("First = %d, Second = %d", firstNum, secondNum);
    }
    return 0;
}

To Run a Program

1. Go to the location/directory where your program is present.
2. g++ proramName.c -o out
3. ./out  5 4

Example:

Input: firstNum=5, secondNum=4
Output: Numbers before swap:
First = 5, Second = 4
Numbers after swap:
First = 4, Second = 5