C Program to calculate the salesmen salary with macro functions.

In C programming, macro functions provide a way to define constants and simple calculations that are processed during compilation. This program demonstrates how to calculate a salesman's salary using predefined macro constants for base salary, bonus rates, and commission percentages.

Problem Statement

A laptop manufacturing company has the following monthly compensation policy for their salespersons −

• Minimum base salary: 3000.00
• Bonus for every laptop sold: 200.00
• Commission on total monthly sales: 5 percent

Since laptop prices change monthly, the sales price of each laptop is fixed at the beginning of every month.

Syntax

#define MACRO_NAME value
#define BASIC_SALARY 3000.00
#define BONUS_RATE 200.00
#define COMMISSION 0.05

Solution Logic

The salary calculation follows this approach −

• Bonus calculation: bonus = BONUS_RATE * quantity
• Commission calculation: commission = COMMISSION * quantity * price
• Gross salary: basic_salary + bonus + commission

Example

The following C program calculates the salesman's salary using macro functions −

#include <stdio.h>

#define BASIC_SALARY 3000.00
#define BONUS_RATE 200.00
#define COMMISSION 0.05

int main() {
    int quantity;
    float gross_salary, price;
    float bonus, commission;
    
    printf("Enter number of items sold and their price: ");
    scanf("%d %f", &quantity, &price);
    
    bonus = BONUS_RATE * quantity;
    commission = COMMISSION * quantity * price;
    gross_salary = BASIC_SALARY + bonus + commission;
    
    printf("<br>--- Salary Breakdown ---<br>");
    printf("Basic Salary = %.2f<br>", BASIC_SALARY);
    printf("Bonus = %.2f<br>", bonus);
    printf("Commission = %.2f<br>", commission);
    printf("Gross Salary = %.2f<br>", gross_salary);
    
    return 0;
}

Enter number of items sold and their price: 20 15000
--- Salary Breakdown ---
Basic Salary = 3000.00
Bonus = 4000.00
Commission = 15000.00
Gross Salary = 22000.00

Key Points

• Macro constants are defined using #define directive and processed during compilation
• Macros improve code readability and make it easy to modify values
• The commission is calculated as 5% of total sales (quantity × price)
• Bonus is a fixed amount per laptop sold

Conclusion

Using macro functions in C provides an efficient way to define constants for salary calculations. This approach makes the code more maintainable and allows easy modification of compensation rates when company policies change.