C++ If-Else

If-Else:

In C++, the 'if-else' statement is used for decision-making. It allows you to execute a block of code if a particular condition is true, and another block if the condition is false. You can also nest 'if-else' statements to create more complex decision structures.

Here's a simple example of an 'if-else' statement:

#include＜iostream＞

int main() {
    int number;

    std::cout << "Enter a number: ";
    std::cin >> number;

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

    return 0;
}

Enter a number: 1
The number is positive.

* In this example, if the entered number is greater than 0, it prints that the number is positive; otherwise, it prints that the number is non-positive.

Nested If-Else:

You can use nested if-else statements to create a series of conditions and execute different blocks of code based on those conditions. Now, let's look at an example of nested if-else statements:

#include＜iostream＞

int main() {
    int x = 10;
    int y = 20;

    if (x > y) {
        std::cout << "x is greater than y" << std::endl;
    } else {

//nested if-else
        if (x < y) {
            std::cout << "x is less than y" << std::endl;
        } else {
            std::cout << "x is equal to y" << std::endl;
        }
    }
    return 0;
}

In this example, the outer if-else statement checks if 'x' is greater than 'y'. If true, it prints a message. If false, it enters the else block and checks if 'x' is less than 'y' in the inner if-else statement. If this is true, it prints a different message; otherwise, it prints another message indicating that 'x' is equal to 'y'.

x is less than y

Note: Remember that you can nest if-else statements to create more complex decision trees, but be mindful of code readability.