Conditional operator

& and | are bitwise operators that occurs in many programming languages. The major difference is that bitwise operations operate on the individual bits of a binary numeral, whereas conditional operators operate on logical operations. Additionally, expressions before and after a bitwise operator will always be evaluated.

if (expression1 || expression2 || expression3)

If expression 1 is true, expression 2 and 3 will NOT be checked.

if (expression1 | expression2 | expression3)

This will check expression 2 and 3, even if 1 is already true.

Short circuit operators can reduce run-time by avoid calling later functions. They can also avoid Null Exception if expression 1 check whether an object is valid.

?: is used in conditional expressions. Programmers can rewrite an if-then-else expression in a more concise way by using the conditional operator.[3]

condition ? expression 1 : expression 2

condition: An expression which is evaluated as a boolean value.

expression 1, expression 2: Expressions with values of any type.

If the condition is evaluated to true, the expression 1 will be evaluated. If the condition is evaluated to false, the expression 2 will be evaluated.

It should be read as: "If condition is true, assign the value of expression 1 to result. Otherwise, assign the value of expression 2 to result."

The conditional operator is right-associative, meaning that operations are grouped from right to left. For example, an expression of the form a ? b : c ? d : e is evaluated as a ? b : (c ? d : e).[2]

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).

#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]

// 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 in C#:

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

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

Conditional operator of JavaScript is compatible with 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]

The ternary operator is right-associative, which means it can be "chained" in the following way, similar to an if ... else if ... else if ... else chain.[4]

the conditional operator can yield a L-value in C/C++ which can be assigned another value, but the vast majority of programmers consider this extremely poor style, if only because the technique's obscurity.[6]