Ternary Operator

The ternary operator in Java is a conditional operator used to make decisions in a single line of code. It is often used as a compact alternative to if-else statements. This topic is commonly asked in interviews and frequently used in clean, concise Java code.

What Is the Ternary Operator?

• A conditional operator
• Takes three operands
• Returns a value based on a condition

Syntax:

condition ? expression1 : expression2;
          

How the Ternary Operator Works

• If the condition is true → expression1 is executed
• If the condition is false → expression2 is executed

Basic Example

int a = 10;
int b = 20;
int max = (a > b) ? a : b;
System.out.println(max);  // 20
          

Ternary Operator vs if-else

Using if-else

int result;
if (a > b) {
    result = a;
} else {
    result = b;
}
          

Using Ternary Operator

int result = (a > b) ? a : b;
          

Why it matters: Ternary operator makes code shorter and more readable for simple conditions.

Using Ternary Operator with Different Data Types

With Strings

String status = (age >= 18) ? "Adult" : "Minor";
          

With Method Calls

int result = (isValid) ? calculateA() : calculateB();
          

Nested Ternary Operator (Advanced)

Used for multiple conditions, but should be used carefully.

int max = (a > b) ? (a > c ? a : c) : (b > c ? b : c);
          

Interview Tip: Nested ternary is valid but can reduce readability.

Ternary Operator with Assignment

boolean isLoggedIn = true;
String message = isLoggedIn ? "Welcome" : "Please login";
          

Type Compatibility Rules

• Both expressions must return compatible types
• Java performs type promotion if needed

int x = true ? 10 : 20;   // valid

// int x = true ? 10 : 10.5; ❌ invalid
          

Common Beginner Mistakes

• Using ternary for complex logic
• Forgetting parentheses in nested ternary
• Mixing incompatible return types
• Overusing ternary, reducing readability

Interview-Ready Answers

Short Answer

The ternary operator is a conditional operator used to make decisions in a single line.

Detailed Answer

The ternary operator (? :) evaluates a condition and returns one of two values based on whether the condition is true or false. It is commonly used as a compact alternative to if-else for simple conditional logic.

Key Takeaway

The ternary operator improves code conciseness, but should be used only for simple conditions to maintain readability.