C++ Code Example: simple if-else statement

In this C++ program, a variable of type boolean is declared and initialized with the value false. The “!” character in front of a boolean variable inverts the expression. The if statement checks whether the variable isSet is false. If such a case should arise, the variable is set to true.

Code Example

The code initializes a boolean variable isSet to false, and then checks if isSet is false using an if statement with a negation operator !. If isSet is indeed false, the code sets its value to true using an assignment operator =.

Finally, the code prints the string “true” to the console if isSet is equal to 1 (which is equivalent to true), and “false” otherwise. This is done using the ternary operator ? :, which is a shorthand for an if–else statement. The ternary operator has the form condition ? value_if_true : value_if_false, and returns value_if_true if condition is true, and value_if_false otherwise. In this case, the condition is (isSet == 1) which evaluates to true if isSet is equal to 1, and value_if_true is the string “true”, while value_if_false is the string “false”.

#include <iostream>
using namespace std;

int main() {
    bool isSet = false;

    if (!isSet)
        isSet = true;

    cout << (isSet == 1 ? "true" : "false");

    return 0;
}

Output

true