If Example in Java

Introduction

If 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();
	}

Syntax Example

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

Syntax Explanation

consider above example syntax,

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

If Example Program

import java.util.Scanner;

class IfExample{
	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 that the given number "+num+" is egual to 5 is : True ");
		}
	}
}

Sample Output

Enter the number:
5
 Condition that the given number 5 is egual to 5 is : True

When to use

Use this if 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. Compare your console output with the sample output for If to confirm the program behaves correctly.

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.