Conditional operator - Wikiwand

Java

class ConditionalDemo2 {
    public static void main(String[] args) {
        int value1 = 1;
        int value2 = 2;
        int result;
        boolean someCondition = true;
        result = someCondition ? value1 : value2;
        System.out.println(result);
    }
}

In this example, because someCondition is true, this program prints "1" to the screen. Use the ?: operator instead of an if-then-else statement if it makes your code more readable; for example, when the expressions are compact and without side-effects (such as assignments).

C++

#include <iostream>
int main() {
    int x = 1;
    int y = 2;
    std::cout << ( x > y ? x : y ) << " is the greater of the two." << std::endl;
}

There are several rules that apply to the second and third operands in C++:

• If both operands are of the same type, the result is of that type
• If both operands are of arithmetic or enumeration types, the usual arithmetic conversions (covered in Standard Conversions) are performed to convert them to a common type
• If both operands are of pointer types or if one is a pointer type and the other is a constant expression that evaluates to 0, pointer conversions are performed to convert them to a common type
• If both operands are of reference types, reference conversions are performed to convert them to a common type
• If both operands are of type void, the common type is type void
• If both operands are of the same user-defined type, the common type is that type.^[4]

C#

// condition ? first_expression : second_expression;
static double sinc(double x) 
{
    return x != 0.0 ? Math.Sin(x)/x : 1.0;
}

There are several rules that apply to the second and third operands x and y in C#:

• If x has type X and y has type Y:
• If an implicit conversion exists from X to Y but not from Y to X, Y is the type of the conditional expression.
• If an implicit conversion exists from Y to X but not from X to Y, X is the type of the conditional expression.
• Otherwise, no expression type can be determined, and a compile-time error occurs.
• If only one of x and y has a type, and both x and y are implicitly convertible to that type, that type is the type of the conditional expression.
• Otherwise, no expression type can be determined, and a compile-time error occurs.^[2]

JavaScript

var age = 26;
var beverage = (age >= 21) ? "Beer" : "Juice";
console.log(beverage); // "Beer"

The conditional operator of JavaScript is compatible with the following browsers:

Chrome, Edge, Firefox (1), Internet Explorer, Opera, Safari, Android webview, Chrome for Android, Edge Mobile, Firefox for Android (4), Opera for Android, Safari on IOS, Samsung Internet, Node.js.^[5]

JavaScript

function example(…) {
   		 return condition1 ? value1
        		: condition2 ? value2
         		: condition3 ? value3
         		: value4;
}
// Equivalent to:
function example(…) {
    	if (condition1) { return value1; }
  		else if (condition2) { return value2; }
   		else if (condition3) { return value3; }
    	else { return value4; }
}

C/C++

const double a =
	expression1	? a1
	: expression2	? a2
	: expression3	? a3
	: /*otherwise*/	a4;
// Equivalent to:
double a;
  if (expression1)
	a = a1;
  else if (expression2)
	a = a2;
  else if (expression3)
	a = a3;
  else /*otherwise*/
	a = a4;