Definition

The question mark operator (? :) is a conditional operator that selects one of two expressions based on the evaluation result of a condition. It can achieve results similar to an if statement.

Structure

if (Condition) {
    result = expression1;
} else {
    result = expression2;
}

result = Condition ? expression1 : expression2;

It is equivalent to an if statement.

Considerations for Use

When using the ternary operator, the following considerations should be taken into account:

Advantages

• Code Conciseness: It allows expressing logic where a value is chosen based on a condition in a single line, enhancing code readability and conciseness.

• Expression Reusability: The selected expression can be assigned to a variable or used as part of other expressions, thus increasing reusability.

Disadvantages

• Readability of Complex Conditions: While the ternary operator is suitable for simple conditions, it may reduce readability for complex condition expressions. In such cases, using if-else statements might be more appropriate.

Step-by-Step Usage

1. Write the condition expression. The condition expression should evaluate to a boolean value (true or false).

2. Follow the condition expression with a question mark (?).

3. Write the expression to be selected if the condition is true, followed by a colon (:).

4. Write the expression to be selected if the condition is false.

5. The result of the ternary operator is the value of the selected expression.

Example

int age = 18;
String message = (age >= 18) ? "You are an adult." : "You are a minor.";

System.out.println(message); // Output: "You are an adult."

In the example above, the value of the age variable is 18 or older, so the condition (age >= 18) evaluates to true. Therefore, the expression1, "You are an adult.", is selected and assigned to the message variable.