Module 2

Control flow statement :

1. Control flow statement decide which statement is execute, how many times it runs, which order it runs.

Types of control flow statement :

1. Decision making statement
2. Looping statement
3. Jumping statement

Decision making statement :

1. Decision making statement take decision based on the condition.

If statement :

1. if is a java keyword.

2. Execute code only if condition is true.

Else statement :

1. else is a java keyword.

2. Execute code only when if condition is false.

Else-if statement :

1. else if is a java keyword.

2. If we want check multiple condition , we go for else-if statement.

Switch case :

1. Switch-case is used when you want to execute different code based on one value.

2. Switch case allowed these primitive data type such as byte, short, int, char in expression.

3. If no case matches, the default block will execute.

Switch case syntax :

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

Example code 1 :

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");
}

Example code 2 :

char grade = 'A';

switch (grade) {
    case 'A':
    case 'B':
    case 'C':
        System.out.println("Passed");
        break;
    case 'D':
        System.out.println("Failed");
}

After java 8 features :

1. Switch case allowed String data type in expression after java 8th version.

After java 12+ version :

1. If we use arrow symbol in switch case, don't need to mention break keyword.

Example code 1 :

char grade = 'A';

switch (grade) {
    case 'A', 'B', 'C' -> System.out.println("Passed");
    case 'D' -> System.out.println("Failed");
}

Example code 2 :

int day =1;
        int result = switch (day) {
        case 1 -> 10;
        case 2 -> 20;
        default -> 0;
    };

Example code 3 :

int day = 1;
int result = switch (day) {
    case 1 -> 10;
    case 2 -> 20;
    default -> 0;
};