If else if statement in Java

The if-else-if statement is a fundamental building block in Java programming, allowing developers to control the flow of their programs based on multiple conditions.

In some cases, we need if else if ladder statement for solving the problem. For example, we have to check multiple conditions in the program and then use if-else-if conditional statements. In this article, we understand the concept easily.

What is If Else If in Java?

Here, we check multiple conditions. First, the if condition is checked (true or false), if the condition is true then if block statements will be executed and if the condition is false then if block statements will not executed and control will be transferred to the next else-if condition.

Now, else-if condition is checked, if the else-if condition is true then else-if block statements will be executed and if the condition is false the else-if block will not executed and control will be transferred to the next else-if condition if it exists.

We can write N numbers of else-if conditions in the Java program.

In the if-else-if statement, the last block is the else block. If all conditions are false then else block will be executed.

Syntax:

if (condition1) {
    // Block of code to execute if condition1 is true
} else if (condition2) {
    // Block of code to execute if condition1 is false and condition2 is true
} else if (condition3) {
    // Block of code to execute if condition1 
   // and condition2 are false and condition3 is true
} else {
    // Block of code to execute if none of the above conditions are true
}

if (condition1) {
    // Block of code to execute if condition1 is true
} else if (condition2) {
    // Block of code to execute if condition1 is false and condition2 is true
} else if (condition3) {
    // Block of code to execute if condition1 
   // and condition2 are false and condition3 is true
} else {
    // Block of code to execute if none of the above conditions are true
}

If else if Flowchart

Explanation:

let’s understand if-else-if with the help of a flowchart, how it works.

1. First control starts from the top, if condition is checked if the condition is true then if block statement means statement 1 will be executed and after execution control is transferred to the next statement in the program.
2. If the condition is false, then else-if condition 2 will be checked if the else-if condition 2 is true then else-if block statement means statement 2 will be executed and after execution control is transferred to the next statement in the program.
3. If the else-if condition 2 is false, then else-if condition 3 will be checked if the else-if condition 3 is true then statement 3 will be executed and after execution control is transferred to the next statement in the program.
4. We can write N number of else-if conditions.
5. When all conditions are false then the default else block will be executed and after execution control is transferred to the next statement in the program.

Now we understand the if-else-if ladder programs for better understanding.

Program 1: Simple Tax Bracket Calculator

This program calculates the tax bracket based on the annual income.

public class TaxBracketCalculatorDemo {
    public static void main(String[] args) {
        double annualIncome = 49000; // Annual income in dollars

        // Determine the tax bracket based on annual income
        if (annualIncome > 200000) {
            System.out.println("Tax Bracket: Very High Income (" + annualIncome + ")");
        } else if (annualIncome > 51000) {
            System.out.println("Tax Bracket: High Income (" + annualIncome + ")");
        } else if (annualIncome > 30000) {
            System.out.println("Tax Bracket: Low-Middle Income (" + annualIncome + ")");
        } else {
            System.out.println("Tax Bracket: Low Income (" + annualIncome + ")");
        }
        
        // This statement always executes
        System.out.println("Outside the if-else-if block");
    }
}

public class TaxBracketCalculatorDemo {
    public static void main(String[] args) {
        double annualIncome = 49000; // Annual income in dollars

        // Determine the tax bracket based on annual income
        if (annualIncome > 200000) {
            System.out.println("Tax Bracket: Very High Income (" + annualIncome + ")");
        } else if (annualIncome > 51000) {
            System.out.println("Tax Bracket: High Income (" + annualIncome + ")");
        } else if (annualIncome > 30000) {
            System.out.println("Tax Bracket: Low-Middle Income (" + annualIncome + ")");
        } else {
            System.out.println("Tax Bracket: Low Income (" + annualIncome + ")");
        }
        
        // This statement always executes
        System.out.println("Outside the if-else-if block");
    }
}

Explanation:

1. Variable Initialization:
   • The variable annualIncome is set to 49000, which represents the person’s annual income in dollars.
2. If-Else-If Ladder:
   • The program checks the value of annualIncome using an if-else-if ladder to determine the tax bracket.
     • First Condition: If annualIncome is greater than 200,000, it prints “Tax Bracket: Very High Income”.
     • Second Condition: If annualIncome is between 51,000 and 200,000, it prints “Tax Bracket: High Income”.
     • Third Condition: If annualIncome is between 30,000 and 51,000, it prints “Tax Bracket: Low-Middle Income”.
     • Else: For incomes 30,000 or below, it prints “Tax Bracket: Low Income”.
3. Final Statement:
   • After the if-else-if block, the program prints “Outside the if-else-if block”. This statement will always execute regardless of the value of annualIncome.

Output:

For an annualIncome of 49000, the output will be:

Tax Bracket: Low-Middle Income (49000.0)
Outside the if-else-if block

Program 2: Age Category Identifier

This program identifies the age category based on the person’s age.

public class AgeCategoryIdentifier {
    public static void main(String[] args) {
        int age = 25; // Person's age

        // Determine the age category based on age
        if (age >= 66) {
            System.out.println("Category: Senior");
            System.out.println("Person is a Senior with age " + age);
        } else if (age >= 34) {
            System.out.println("Category: Adult");
            System.out.println("Person is an Adult with age " + age);
        } else if (age >= 18) {
            System.out.println("Category: Young Adult");
            System.out.println("Person is a Young Adult with age " + age);
        } else {
            System.out.println("Category: Minor");
            System.out.println("Person is a Minor with age " + age);
        }
    }
}

public class AgeCategoryIdentifier {
    public static void main(String[] args) {
        int age = 25; // Person's age

        // Determine the age category based on age
        if (age >= 66) {
            System.out.println("Category: Senior");
            System.out.println("Person is a Senior with age " + age);
        } else if (age >= 34) {
            System.out.println("Category: Adult");
            System.out.println("Person is an Adult with age " + age);
        } else if (age >= 18) {
            System.out.println("Category: Young Adult");
            System.out.println("Person is a Young Adult with age " + age);
        } else {
            System.out.println("Category: Minor");
            System.out.println("Person is a Minor with age " + age);
        }
    }
}

Explanation:

1. Variable Initialization:
   • The variable age is set to 25, representing the person’s age in years.
2. If-Else-If Ladder:
   • The program uses an if-else-if ladder to categorize the age:
     • First Condition: If age is 66 or older, it prints “Category: Senior” and “Person is a Senior with age [age]”.
     • Second Condition: If age is between 34 and 65, it prints “Category: Adult” and “Person is an Adult with age [age]”.
     • Third Condition: If age is between 18 and 33, it prints “Category: Young Adult” and “Person is a Young Adult with age [age]”.
     • Else: For ages below 18, it prints “Category: Minor” and “Person is a Minor with age [age]”.

Output:

For an age of 25, the output will be:

Category: Young Adult
Person is a Young Adult with age 25

Tip: Put the most specific conditions first

Conclusion

The If Else If ladder is a crucial control structure in Java for managing multiple conditions effectively. It allows for clear and organized decision-making by evaluating a series of conditions in sequence. Understanding and mastering this technique will enhance your programming skills and make your code more efficient and maintainable. Use the If Else If ladder to tackle complex scenarios with greater clarity and precision in your Java projects.