Control Statements in Java: if, switch, Loops Explained

Introduction

Control statements in Java are used to control the flow of execution of a program. By default, Java programs execute statements one after another in a sequential manner. However, real-world programs need to make decisions, repeat tasks, and execute different blocks of code based on conditions. This is where control statements become essential.

Control statements allow a program to:

Make decisions
Execute code repeatedly
Choose between multiple paths

Understanding control statements is crucial for writing logical, dynamic, and efficient Java programs. In this article, you will learn the types of control statements in Java, their usage, simple examples, and common mistakes beginners should avoid.

What Are Control Statements in Java?

Control statements determine which statement will execute next based on conditions or loops. They help implement logic such as decision-making and repetition in Java programs.

Types of Control Statements in Java

Java control statements are broadly divided into three categories:

Decision-Making Statements
Looping Statements
Jump Statements

types of control statements in java diagram

1. Decision-Making Statements

Decision-making statements allow the program to execute different code blocks based on conditions.

if Statement

The if statement executes a block of code only when a condition is true.

int age = 20;

if (age >= 18) {
    System.out.println("Eligible to vote");
}

if-else Statement

The if-else statement executes one block if the condition is true and another if it is false.

int number = 5;

if (number % 2 == 0) {
    System.out.println("Even number");
} else {
    System.out.println("Odd number");
}

if-else-if Ladder

Used when there are multiple conditions to evaluate.

int marks = 75;

if (marks >= 90) {
    System.out.println("Grade A");
} else if (marks >= 60) {
    System.out.println("Grade B");
} else {
    System.out.println("Grade C");
}

switch Statement

The switch statement selects execution paths based on a variable’s value.

int day = 3;

switch (day) {
    case 1: System.out.println("Monday"); break;
    case 2: System.out.println("Tuesday"); break;
    case 3: System.out.println("Wednesday"); break;
    default: System.out.println("Invalid day");
}

2. Looping Statements

Looping statements are used to repeat a block of code until a condition is met.

for Loop

Used when the number of iterations is known.

for (int i = 1; i <= 5; i++) {
    System.out.println(i);
}

while Loop

Executes a block of code as long as the condition is true.

int i = 1;

while (i <= 5) {
    System.out.println(i);
    i++;
}

do-while Loop

Executes the loop at least once, even if the condition is false.

int i = 1;

do {
    System.out.println(i);
    i++;
} while (i <= 5);

Loop Execution Flow

3. Jump Statements

Jump statements are used to transfer control immediately.

break Statement

Used to terminate a loop or switch statement.

for (int i = 1; i <= 5; i++) {
    if (i == 3) {
        break;
    }
    System.out.println(i);
}

continue Statement

Skips the current iteration and continues with the next one.

for (int i = 1; i <= 5; i++) {
    if (i == 3) {
        continue;
    }
    System.out.println(i);
}

Why Control Statements Are Important?

Control statements help Java programs:

Make decisions
Repeat tasks efficiently
Reduce code duplication
Implement real-world logic
Improve readability and structure

Without control statements, Java programs would be limited to straight-line execution.

Common Beginner Mistakes

Forgetting braces {} in if statements
Infinite loops due to missing condition updates
Missing break in switch cases
Confusing while and do-while loops

Avoiding these mistakes improves code reliability.

Key Takeaways

Control statements manage program flow.
Java has decision-making, looping, and jump statements.
if and switch are used for decisions.
Loops repeat code efficiently.
break and continue control loop execution.

Java Interview Questions – Control Statements

1. What are control statements in Java?
They control the execution flow of a program.

2. Difference between while and do-while loop?
do-while executes at least once, while while may not.

3. When should you use a switch statement?
When multiple conditions depend on a single variable.

4. What does break do?
It terminates the loop or switch immediately.

5. Can we use if inside a loop?
Yes, control statements can be nested.

What’s Next?

Now that you understand control statements, the next step is learning how to organize logic into reusable blocks.

👉 Methods in Java
Learn method declaration, parameters, return types, and examples.

👉 Arrays in Java
Understand how to store and process multiple values efficiently.

Control Statements in Java: Decision Making and Loops Explained

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