C program to calculate Electricity bill

 Here's a step-by-step explanation to create a C program for calculating an electricity bill using nested if statements. You can use this structure for your blog post:

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Step-by-Step Guide: Calculating Electricity Bill in C Using Nested if

Step 1: Understand the Billing Criteria

Before coding, define the slab system for electricity billing. For example:

First 100 units: ₹1.5 per unit

Next 100 units (101-200): ₹2.5 per unit

Above 200 units: ₹3.5 per unit

Additionally, you can include a fixed charge or tax if needed.

Step 2: Set Up the Program Structure

The program will:

1. Take the number of units consumed as input.

2. Use nested if statements to calculate the total bill based on the slabs.

3. Display the total bill amount.

Step 3: Write the C Code

Here’s a sample code snippet:

#include <stdio.h>

int main() {

    int units;

    float bill = 0.0;

    // Prompt the user for the number of units consumed

    printf("Enter the number of units consumed: ");

    scanf("%d", &units);

    // Calculate the electricity bill using nested if

    if (units <= 100) {

        // For the first 100 units

        bill = units * 1.5;

    } else {

        if (units <= 200) {

            // For the next 100 units

            bill = (100 * 1.5) + ((units - 100) * 2.5);

        } else {

            // For units above 200

            bill = (100 * 1.5) + (100 * 2.5) + ((units - 200) * 3.5);

        }

    }

    // Print the total bill

    printf("The total electricity bill is: ₹%.2f\n", bill);

    return 0;

}

Step 4: Explain the Nested if Logic

1. The outer if checks if the units are less than or equal to 100. If true, the bill is calculated using ₹1.5 per unit.

2. If units exceed 100, the inner if checks if the units are less than or equal to 200. It calculates the bill for the first 100 units and the remaining units in this range.

3. If units are more than 200, the program calculates the bill for all three slabs.

Step 5: Test the Program

Run the program with different inputs to ensure:

For 50 units, it calculates correctly: ₹75.

For 150 units, it calculates: ₹275 (₹150 for first 100 units + ₹125 for the next 50 units).

For 250 units, it calculates: ₹450 (₹150 + ₹250 + ₹50).

Step 6: Optional Enhancements

You can extend the program by:

Adding a fixed meter charge, e.g., ₹50.

Including late payment fees for overdue bills.

Allowing the user to input slab rates dynamically.

Final Note

Using nested if statements ensures readability and logical separation for slab-wise calculation. It's simple yet effective for beginners to learn conditional programming.

Watch this video to get practical demonstration in Code Block to calculate electricity bill in C: