?:

In case the statement associated with if and the statement associated with else are both expressions, an alternative more concise form can be used:

int a;
cin >> a;

a > 3 ? 10 : 20;

The statement above means “if a is greater than 3 the overall expression evaluates to 10, otherwise it evaluates to 20”. As the statement evaluates to one of two expressions (in the case above, simply 10 or 20) it can be assigned to an lvalue of a proper type.

Example


#include <iostream>
#include <cmath>// necessary to use the function pow, which calculates a power
using namespace std;

int main()
{   
    cout << "Enter a value, please ";
    int a;
    cin >> a;

    int x = a > 3 ? 10 : 20;
    cout << "x\'s value is " << x << endl;

    double y = a > 3 ? pow(10, 2) : pow(20, 2);
    cout << "y\'s value is " << y << endl;

}

Output

Enter a value, please 4
x's value is 10
y's value is 100

C++

?:

Example

Output