Conditional and Jump Statements in C++

Conditional and jump statements are essential concepts in C++ that let you control the flow of your program. They enable you to execute code blocks based on conditions or jump to specific sections of your code. In this guide, we'll cover three main constructs: if-else, switch, and goto.

If-Else Statement

The if-else statement is used to execute a block of code only if a specified condition is true. You can extend it with additional conditions using else if and include a final else block for cases when none of the conditions hold.

Syntax:

if (condition) {
    // Code to execute if condition is true
} else if (anotherCondition) {
    // Code to execute if anotherCondition is true
} else {
    // Code to execute if none of the above conditions are true
}

Example:

#include <iostream>

int main() {
    int number = 10;

    if (number > 0) {
        std::cout << "The number is positive." << std::endl;
    } else if (number < 0) {
        std::cout << "The number is negative." << std::endl;
    } else {
        std::cout << "The number is zero." << std::endl;
    }

    return 0;
}

Switch Statement

The switch statement is used for multi-way branching based on the value of an expression. It compares the expression to a series of constant cases and executes the corresponding block. Use the break statement to exit the switch after a case is executed, and include a default case to handle values that do not match any case.

Syntax:

switch (expression) {
    case constant1:
        // Code block for constant1
        break;
    case constant2:
        // Code block for constant2
        break;
    // You can have as many cases as needed
    default:
        // Code block if no cases match
}

Example:

#include <iostream>

int main() {
    char grade = 'B';

    switch (grade) {
        case 'A':
            std::cout << "Excellent!" << std::endl;
            break;
        case 'B':
            std::cout << "Good job!" << std::endl;
            break;
        case 'C':
            std::cout << "Well done!" << std::endl;
            break;
        default:
            std::cout << "Grade not recognized." << std::endl;
    }

    return 0;
}

Goto Statement

The goto statement provides an unconditional jump from the goto to a labeled statement within the same function. Although its use is generally discouraged due to potential impacts on code readability and maintainability, it can be useful in scenarios like breaking out of deeply nested loops.

Syntax:

goto labelName;
// ...
labelName:
    // Code to execute after jump

Example:

#include <iostream>

int main() {
    int count = 0;

start:
    std::cout << "Count is: " << count << std::endl;
    count++;

    if (count < 5)
        goto start;  // Jump back to the label 'start'

    return 0;
}

Summary

If-Else: Allows decision-making by executing different code blocks based on conditions.
Switch: Offers a cleaner syntax for handling multiple discrete values of an expression.
Goto: Provides a way to jump to a specific label; use it sparingly to keep your code clear.

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Conditional and Jump Statements in C++

If-Else Statement

Switch Statement

Goto Statement

Summary

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