In Java, a ternary operator can be used to replace the if...else statement in certain situations. Before you learn about the ternary operator, make sure you visit Java if...else statement.
Ternary Operator in Java
A ternary operator evaluates the test condition and executes a block of code based on the result of the condition.
Its syntax is:
condition ? expression1 : expression2;
Here, condition is evaluated and
- if condition is
true
, expression1 is executed. - And, if condition is
false
, expression2 is executed.
The ternary operator takes 3 operands (condition, expression1, and expression2). Hence, the name ternary operator.
Example: Java Ternary Operator
import java.util.Scanner;
class Main {
public static void main(String[] args) {
// take input from users
Scanner input = new Scanner(System.in);
System.out.println("Enter your marks: ");
double marks = input.nextDouble();
// ternary operator checks if
// marks is greater than 40
String result = (marks > 40) ? "pass" : "fail";
System.out.println("You " + result + " the exam.");
input.close();
}
}
Output 1
Enter your marks: 75 You pass the exam.
Suppose the user enters 75. Then, the condition marks > 40
evaluates to true
. Hence, the first expression pass is assigned to result.
Output 2
Enter your marks: 24 You fail the exam.
Now, suppose the user enters 24. Then, the condition marks > 40
evaluates to false
. Hence, the second expression fail is assigned to result.
When to use the Ternary Operator?
In Java, the ternary operator can be used to replace certain types of if...else
statements. For example,
You can replace this code
class Main {
public static void main(String[] args) {
// create a variable
int number = 24;
if(number > 0) {
System.out.println("Positive Number");
}
else {
System.out.println("Negative Number");
}
}
}
with
class Main {
public static void main(String[] args) {
// create a variable
int number = 24;
String result = (number > 0) ? "Positive Number" : "Negative Number";
System.out.println(result);
}
}
Output
Positive Number
Here, both programs give the same output. However, the use of the ternary operator makes our code more readable and clean.
Note: You should only use the ternary operator if the resulting statement is short.
Nested Ternary Operators
It is also possible to use one ternary operator inside another ternary operator. It is called the nested ternary operator in Java.
Here's a program to find the largest of 3 numbers using the nested ternary operator.
class Main {
public static void main(String[] args) {
// create a variable
int n1 = 2, n2 = 9, n3 = -11;
// nested ternary operator
// to find the largest number
int largest = (n1 >= n2) ? ((n1 >= n3) ? n1 : n3) : ((n2 >= n3) ? n2 : n3);
System.out.println("Largest Number: " + largest);
}
}
Output
Largest Number: 9
In the above example, notice the use of the ternary operator,
(n1 >= n2) ? ((n1 >=n3) ? n1 : n3) : ((n2 >= n3) ? n2 : n3);
Here,
- (n1 >= n2) - first test condition that checks if n1 is greater than n2
- (n1 >= n3) - second test condition that is executed if the first condition is
true
- (n2 >= n3) - third test condition that is executed if the first condition is
false
Note: It is not recommended to use nested ternary operators. This is because it makes our code more complex.