Control Statements in Java: if-else, switch, and Loops Explained

7/19/2025
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Diagram of Control Statements in Java: if-else.

Control Statements in Java: if-else, switch, and Loops Explained

Control Statements in Java: if-else, switch, and Loops Explained

Control Statements in Java

Control statements allow you to control the flow of execution in a Java program. They include conditional statements like if-else and switch, as well as looping structures like for, while, and do-while.

Let’s explore how they work with examples.

1. if-else Statement

The if-else statement is used to execute code blocks based on conditions.

Syntax:

if (condition) {
    // code if true
} else {
    // code if false
}

Example:

int number = 10;
if (number > 0) {
    System.out.println("Positive number");
} else {
    System.out.println("Non-positive number");
}

 2. if-else if Ladder

Used for checking multiple conditions.

Example:

int marks = 85;
if (marks >= 90) {
    System.out.println("Grade A");
} else if (marks >= 75) {
    System.out.println("Grade B");
} else {
    System.out.println("Grade C");
}

3. switch Statement

The switch statement is an alternative to multiple if-else conditions.

Syntax:

switch (variable) {
    case value1:
        // code
        break;
    case value2:
        // code
        break;
    default:
        // default code
}

Example:

int day = 2;
switch (day) {
    case 1:
        System.out.println("Monday");
        break;
    case 2:
        System.out.println("Tuesday");
        break;
    default:
        System.out.println("Other Day");
}

🔄 4. Loops in Java

Loops execute a block of code multiple times.

A. for Loop

Used when the number of iterations is known.

for (int i = 0; i < 5; i++) {
    System.out.println(i);
}

B. while Loop

Used when the condition is checked before executing the loop.

int i = 0;
while (i < 5) {
    System.out.println(i);
    i++;
}

C. do-while Loop

Executes the block at least once before checking the condition.

int i = 0;
do {
    System.out.println(i);
    i++;
} while (i < 5);

When to Use Which Statement?

  • Use if-else for complex conditions

  • Use switch for multiple fixed values

  • Use for when you know how many times to loop

  • Use while or do-while when the number of iterations is not known in advance

Conclusion

Control statements are essential for building logic in Java programs. With if-else, switch, and loops, you can handle decision-making and repetitive tasks efficiently.

Practice these examples to gain confidence and build more dynamic Java applications.

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