if else

if-else-java

Exercises Interview question Video Tutorial Discussion

Conditional statements are essential in Java for controlling the flow of your program based on specific conditions. The if-else construct is one of the most commonly used conditional structures, allowing your code to make decisions and execute different blocks depending on whether a condition is true or false.

What is if-else?

The if-else statement lets you execute a block of code if a condition is true, and a different block if the condition is false.

Syntax:

if (condition) {
    // Executes if condition is true
} else {
    // Executes if condition is false
}

Types of if Statements in Java

Java offers several variations of the if statement to handle different decision-making scenarios:

1. Simple if Statement

Executes a block of code only if the specified condition is true.

Example:

public class IfStatement {
    public static void main(String[] args) {
        int a = 10, b = 20;
        if (a < b) {
            System.out.println("True");
        }
    }
}

Output:

True

2. if-else Statement

Executes one block if the condition is true, and another block if it is false.

Example:

public class IfElseStatement {
    public static void main(String[] args) {
        int a = 10, b = 20;
        if (a > b) {
            System.out.println("True");
        } else {
            System.out.println("False");
        }
    }
}

Output:

False

3. if-else-if Ladder

Allows you to check multiple conditions in sequence. The first true condition’s block is executed; if none are true, the else block runs.

Example:

public class IfElseIfStatement {
    public static void main(String[] args) {
        int a = 10, b = 20, c = 30;
        if (a > b) {
            System.out.println("a is greater than b");
        } else if (b < c) {
            System.out.println("b is less than c");
        } else {
            System.out.println("No condition matched");
        }
    }
}

Output:

b is less than c

4. Nested if Statement

Places one if statement inside another, enabling you to check multiple related conditions.

Example:

public class NestedIfStatement {
    public static void main(String[] args) {
        int age = 61;
        if (age >= 18) {
            if (age >= 18 && age <= 60) {
                System.out.println("You are Eligible for Driving License");
            } else {
                System.out.println("You are Not Eligible for Driving License");
            }
        } else {
            System.out.println("You are Not Eligible for Driving License");
        }
    }
}

Output:

You are Not Eligible for Driving License

Key Points

The if statement checks a condition and executes code only if the condition is true.

The if-else structure provides an alternative path if the condition is false.

The if-else-if ladder is useful for multiple conditions.

Nested if statements help handle complex, related checks.

Use Case for if, if-else, if-else-if ladder and Nested if Table

Statement Type	Use Case
if	Single condition, single action
if-else	Two possible actions (true / false )
if-else-if ladder	Multiple conditions, multiple actions
Nested if	Complex conditions, hierarchical checking

Tips: Use clear and meaningful conditions to make your code easy to read and maintain. Proper indentation and structure help others (and yourself) understand the logic at a glance.