Ternary Operator In C++ (Check Whether A Year If Leap Or Not)

Admin | Tue, 11 Aug, 2020 | 340

Ternary Operator

It is called Ternary Operator because it has 3 operands to operate a statement. It is also known as Conditional Operator or ? : (Questions Mark and Colon) Operator.

The three operands are:

1. Operand1: Condition_part (Here, we write a conditional statement to validate).
2. Operand2: True_part (Here, we write statement to execute if conditional part is true).
3. Operand3: False_part (Here, we write statement to execute if conditional part is false).

Syntax:

`Operand1? Operand2: Operand3;`

In this program, we are using Ternary (Conditional) operator to check whether a Year is Leap Year or not.

Example/program: Given a year and we have to check whether it is Leap year or not using Ternary Operator/Conditional Operator.

Consider the program:

``````/*
C++ program to check whether entered year is Leap year or not
*/

#include <iostream>
using namespace std;

int main()
{
int year;

//input a year
cout<<"\nEnter year: ";
cin>>year;

/*
if( (year%100!=0 && year%4==0) || (year%400==0) )
cout<<year<<" is a Leap year."<<endl;
else
cout<<year<<" is not a Leap year."<<endl;

*/

//using TERNARY OPERATOR/CONDITIONAL OPR/?: OPR
( (year%100!=0 && year%4==0) || (year%400==0) ) ?
cout<<year<<" is Leap year."<<endl :
cout<<year<<" is not a Leap year."<<endl;

return 0;
}
``````

Output

```First run:
Enter year: 2000
2000 is Leap year.

Second run:
Enter year: 2017
2017 is not a Leap year.

Third run:
Enter year: 1900
1900 is not a Leap year.

Fourth run:
Enter year: 2016
2016 is Leap year.
```

program using goto to run program until input year is not 0

``````/*
C++ program to check whether entered year is Leap year or not
*/

#include <iostream>
using namespace std;

int main()
{
int year;

//Label to run again program from here
INIT:
//input a year
cout<<"\nEnter year (ENTER 0 for exit...): ";
cin>>year;

/*
if( (year%100!=0 && year%4==0) || (year%400==0) )
cout<<year<<" is a Leap year."<<endl;
else
cout<<year<<" is not a Leap year."<<endl;

*/

//using TERNARY OPERATOR/CONDITIONAL OPR/?: OPR
( (year%100!=0 && year%4==0) || (year%400==0) ) ?
cout<<year<<" is Leap year."<<endl :
cout<<year<<" is not a Leap year."<<endl;

//////////////
//condition to go to label INIT or end of the program
if(year!=0)
goto INIT;
//////////////
return 0;
}
``````

Output

```Enter year (ENTER 0 for exit...): 2000
2000 is Leap year.

Enter year (ENTER 0 for exit...): 2017
2017 is not a Leap year.

Enter year (ENTER 0 for exit...): 1900
1900 is not a Leap year.

Enter year (ENTER 0 for exit...): 2016
2016 is Leap year.

Enter year (ENTER 0 for exit...): 0
0 is Leap year.```