Core Java - Control Statements (if, else, switch, loops)

6. Control Statements (if, else, switch, loops)

Control statements in Java allow you to control the flow of your program, make decisions, and repeat tasks. In this section of the Core Java tutorial, we'll explore control statements, including 'if' , 'else', 'switch', and various types of loops, with detailed explanations and examples.

'if' Statement:

The 'if' statement is used to execute a block of code only if a specified condition is 'true'. It's one of the most fundamental control structures in Java.

if (condition) {
    // Code to execute if the condition is true
}

int age = 18;
if (age >= 18) {
    System.out.println("You are an adult.");
}

In this example, the code inside the 'if' block is executed because the condition  'age >= 18' is 'true'.

'if-else'Statement:

The 'if-else' statement is used to execute one block of code if a condition is 'true' and another block if the condition is 'false'.

if (condition) {
    // Code to execute if the condition is true
} else {
    // Code to execute if the condition is false
}

int age = 15;
if (age >= 18) {
    System.out.println("You are an adult.");
} else {
    System.out.println("You are not yet an adult.");
}

In this example, the second 'System.out.println' statement is executed because the condition 'age >= 18'is 'false'.

'switch' Statement:

The 'switch' statement is used for multiple branches of execution based on the value of an expression. It's an alternative to using multiple 'if-else' statements.

switch (expression) {
    case value1:
        // Code to execute if expression == value1
        break;
    case value2:
        // Code to execute if expression == value2
        break;
    // ...
    default:
        // Code to execute if expression doesn't match any case
}

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

for (initialization; condition; iteration) {
    // Code to execute repeatedly
}

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

while (condition) {
    // Code to execute repeatedly
}

int count = 0;
while (count < 3) {
    System.out.println("Count: " + count);
    count++;
}

do {
    // Code to execute repeatedly
} while (condition);

int i = 1;
do {
    System.out.println("Iteration " + i);
    i++;
} while (i <= 3);