If Else Example in Java

Introduction

If Else is a classic Java console program that demonstrates the concept with complete source code and sample output. Conditional statements choose different code paths based on boolean expressions.

This tutorial walks through the program line by line, explains how the logic works, and highlights best practices you can apply in your own code.

Definition

IF conditional statement is a feature of this programming language which perform different computations or actions depending on whether a programmer-specified boolean condition evaluates to true or false. Apart from the case of branch predication, this is always achieved by selectively altering the control flow based on some condition.

Syntax

if statements in Java are similar to those in C and use the same syntax:
	if (expression) {
		doSomething();
	}
	else	{
		doSomethingElse();
	}

Syntax Example

for example,
	if (i == 3) {
		doSomething();
	}
	else	{
		doSomethingElse();
	}

Syntax Explanation

Consider above example syntax,if (i == 3)

• which means the variable i contains a number that is equal to 3, the statements following the doSomething() block will be executed.
• Otherwise variable contains a number that is not equal to 3, else block doSomethingElse() will be executed.

If Else Example Program

import java.util.Scanner;

class IfElseExample{
    public static void main(String[] args){
        Scanner in=new Scanner(System.in);
        System.out.println("Enter the number: ");
        int num=in.nextInt();
        if(num==5){
            System.out.println(" Condition of "+num+" equal to 5 is : True ");
        }
        else{
            System.out.println(" Condition of "+num+" equal to 5 is: False ");
        }
    }
}

Sample Output

Enter the number:
56
 Condition of 56 equal to 5 is: False

When to use

Use this if else example when learning or revising core Java syntax.

How it works

1. Execution begins in the main method — the JVM calls this method when you run the class.

2. import java.util.Scanner; imports a class used later in the program.

3. A Scanner reads typed input from the keyboard (System.in).

4. A println / print call writes text to the console — part of the sample output below.

5. int num=in.nextInt(); updates a variable used in the calculation or output.

6. The if statement runs the nested code only when the condition is true.

7. A println / print call writes text to the console — part of the sample output below.

8. A println / print call writes text to the console — part of the sample output below.

Best Practices

• Use meaningful variable and class names that describe their purpose.
• Compile and run the program locally — modify values to see how output changes.
• Read compiler errors carefully; they usually point to the exact line to fix.

Common Mistakes

• Copying code without understanding each line — practice by changing one statement at a time.
• Mismatching the public class name and the .java filename.
• Forgetting semicolons at the end of statements.