Java ternary operator

In this chapter you will learn:

1. How to use the ternary ? Operator
2. Syntax for Java ternary operator
3. Example - Java ternary operator
4. Example - obtain the absolute value of a variable.

Description

The ? operator is a ternary (three-way) operator.

Java ternary operator is basically a short form of simple if statement.

Syntax

The ? has this general form:

expression1 ? expression2 : expression3

expression1 can be any expression that evaluates to a boolean value. If expression1 is true, then expression2 is evaluated. Otherwise, expression3 is evaluated.

The expression evaluated is the result of the ? operation. Both expression2 and expression3 are required to return the same type, which can't be void.

Example

Here is an example of ? operator:

 
public class Main {
  public static void main(String[] argv) {
    int denom = 10;
    int num = 4;//from  w  ww. j a  v  a2  s . co m
    double ratio;

    ratio = denom == 0 ? 0 : num / denom;
    System.out.println("ratio = " + ratio);
  }
}

The output:

Example 2

Here is another program that demonstrates the ? operator. It uses it to obtain the absolute value of a variable.

 
public class Main {
  public static void main(String args[]) {
    int i, k;/*w w w.j a  v a 2  s. c  o m*/
    i = 10;
    k = i < 0 ? -i : i; 
    System.out.print("Absolute value of ");
    System.out.println(i + " is " + k);

    i = -10;
    k = i < 0 ? -i : i; 
    System.out.print("Absolute value of ");
    System.out.println(i + " is " + k);

  }
}

The output generated by the program is shown here:

Next chapter...

What you will learn in the next chapter:

1. What is Java If Statement
2. Syntax for Java If Statement
3. Example - for Java If Statement
4. Example - If statement and comparison operators
5. Example - If statement and single boolean variable

Java ternary operator