Control Structures in C++: If-Else Statements

Understanding If-Else Statements in C++

Control structures are essential in programming as they help direct the flow of execution based on certain conditions. One of the most commonly used control structures is the If-Else statement. This allows programmers to execute different blocks of code based on whether a condition evaluates to true or false. In this article, we will explore three diverse examples of Control Structures in C++: If-Else Statements.

Example 1: Basic Grading System

In this example, we will create a simple grading system that assigns a letter grade based on a numerical score.

#include <iostream>
using namespace std;

int main() {
    int score;
    cout << "Enter your score: ";
    cin >> score;

    if (score >= 90) {
        cout << "Grade: A";
    } else if (score >= 80) {
        cout << "Grade: B";
    } else if (score >= 70) {
        cout << "Grade: C";
    } else if (score >= 60) {
        cout << "Grade: D";
    } else {
        cout << "Grade: F";
    }

    return 0;
}

This program prompts the user to enter their score and outputs a corresponding letter grade. The use of If-Else statements allows for multiple conditions to be checked in a structured way.

Notes:

• You can easily modify the score ranges to fit different grading systems.
• Ensure that the input is within a valid range (0-100) for more robustness.

Example 2: Age Verification for Voting

This example demonstrates how to verify if a user is eligible to vote based on their age.

#include <iostream>
using namespace std;

int main() {
    int age;
    cout << "Enter your age: ";
    cin >> age;

    if (age >= 18) {
        cout << "You are eligible to vote.";
    } else {
        cout << "You are not eligible to vote.";
    }

    return 0;
}

Here, the program checks if the user’s age is greater than or equal to 18, which is the common voting age in many countries. Depending on the result, it outputs whether the user is eligible to vote.

Variations:

• You could extend this example by adding different age requirements based on the country.
• Consider incorporating additional checks to handle invalid input.

Example 3: Simple ATM Withdrawal System

In this example, we’ll simulate a basic ATM withdrawal system that processes user requests based on their account balance.

#include <iostream>
using namespace std;

int main() {
    double balance = 500.00; // Initial account balance
    double withdrawal;
    cout << "Enter amount to withdraw: ";
    cin >> withdrawal;

    if (withdrawal > balance) {
        cout << "Insufficient funds!";
    } else if (withdrawal <= 0) {
        cout << "Please enter a valid amount.";
    } else {
        balance -= withdrawal;
        cout << "Withdrawal successful! New balance: $" << balance;
    }

    return 0;
}

In this program, the user is prompted to enter an amount to withdraw. The If-Else statements check if the withdrawal amount is greater than the balance or if it’s a non-positive amount, ensuring the transaction is valid before proceeding.

Important Notes:

• The initial balance is hard-coded here, but in a real application, it would be fetched from a database.
• You can enhance this example to include more functionalities, such as deposit options or transaction history.

By understanding these Examples of Control Structures in C++: If-Else Statements, you can start implementing decision-making capabilities in your applications effectively!