Three Constructs That Govern Statement Flow

⚙️ Three Constructs That Govern Statement Flow

Every Java program (and almost all programming languages) is built using three fundamental control structures:

🔹 1. Sequence

Definition:
The sequence construct means that statements are executed one after another in the same order in which they appear in the program.

Example:

public class SequenceExample { public static void main(String[] args) { int a = 5; int b = 10; int sum = a + b; System.out.println("Sum = " + sum); } }

Explanation:
Here, each line executes sequentially —
first variables are declared → then addition → then output.
No skipping or repetition of statements.

🔹 2. Selection (Decision Making)

Definition:
The selection construct allows the program to choose a path of execution based on a condition.
It uses if, if-else, or switch statements.

Example:

public class SelectionExample {
    public static void main(String[] args) {
        int number = 10;

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

Explanation:
Here, the program selects one path depending on whether the condition number % 2 == 0 is true or false.

🔹 3. Iteration (Looping)

Definition:
The iteration construct allows statements to be executed repeatedly as long as a condition is true.
It uses loops such as for, while, or do-while.

Example:

public class IterationExample {
    public static void main(String[] args) {
        for (int i = 1; i <= 5; i++) {
            System.out.println("Count: " + i);
        }
    }
}

Explanation:
The statement inside the loop executes five times, controlling the flow through repetition.

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