In Java, decision-making is done using conditional statements. The if statement is one of the most important conditional statements used to execute a block of code only when a specified condition is true. It helps programs make decisions just like humans do in real life. This article focuses on discussing the if statement in detail.
 

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if Statement 

An if statement checks a condition and executes a block of code only if that condition evaluates to true.
Syntax:

if(condition)
{
     // code to execute if condition is true
}

Here,

• 'if' is a keyword in Java.
• The condition written inside brackets must return either true or false.
• If the condition is true, then only the code is written inside the block will execute.
• If the condition is false, then the block is skipped.

Example 1: Check Eligibility to Vote

Below is the Java program that checks whether a person is eligible to vote based on their age.

// Java program to check whether a person
// is eligible to vote based on their age
public class Main 
{
    public static void main(String[] args) 
    {
        int age = 20;
        if(age = 18)
        {
            System.out.println("Eligible to vote");
        }
    }
}

Output:

Eligible to vote

Explanation:

• In the above code if age = 18 is true then block executes. 
• Therefore, the message "Eligible to vote" is printed.

Example 2: Check Pass/ Fail Using Marks

Below is the Java program to determine whether a student has passed or failed based on their marks.

// Java program to determine whether a 
// student has passed or failed based on 
// their marks
public class Main 
{
    public static void main(String[] args) 
    {
        int marks = 30;
        if(marks = 40)
        {
            System.out.println("Pass");
        }
else
{
    System.out.println("Better luck next time");
}
    }
}

Output:

Better luck next time

Explanation:

• In the above code if the marks = 40 is true then only if block will execute. 
• The if block does not execute here because the condition is false.
• So, the control goes to the else statement.

Conclusion

We can conclude that if statement in Java is a fundamental control statement used to make decisions in a program as we do in real life. It checks conditions and executes code accordingly. Understanding if statement is essential for building logical and interactive Java applications.

Frequently Asked Questions

1. What is an if statement in Java?

An if statement in Java is a conditional statement used to execute a block of code only when a specified condition is true.

2. Can we use multiple conditions in an if statement?

Yes, multiple conditions can be used with logical operators like && (AND) and || (OR).

3. What happens if the condition in an if statement is false?

If the condition is false, the code inside the if block is skipped and the program continues executing the remaining statements.

4. Is it mandatory to use curly braces {} in an if statement?

No, curly braces are optional when there is only one statement inside the if block. However, using braces is recommended for better readability.

5. What is the difference between if and if-else statement?

• if executes code only when the condition is true. 
• if-else provides an alternative block that executes when the condition is false.