1: Introduction to if, else if, and else Statements

Conditional statements allow us to execute specific blocks of code based on certain conditions in C programming.

• if Statement:

  int age = 20;

  if (age >= 18) {
printf("You are an adult.n");
}


• else Statement:

  int age = 15;

  if (age >= 18) {
printf("You are an adult.n");
} else {
printf("You are a minor.n");
}


• else if Statement:

  int score = 75;

  if (score >= 90) {
printf("Grade An");
} else if (score >= 80) {
printf("Grade Bn");
} else if (score >= 70) {
printf("Grade Cn");
} else {
printf("Grade Fn");
}


2: Nested if Statements

Nested if statements allow us to include one if or else if statement inside another.

• Example:
  int num = 10;

  if (num > 0) {
if (num % 2 == 0) {
printf("Positive even numbern");
} else {
printf("Positive odd numbern");
}
} else {
printf("Not a positive numbern");
}


3: Ternary Operator

The ternary operator (?:) provides a shorthand way to write if-else statements in a single line.

• Syntax:

  condition ? expression_if_true : expression_if_false;


• Example:

  int num = 12;
num % 2 == 0 ? printf("Evenn") : printf("Oddn");


 4: Practice and Examples

• Practice Exercise:
  • Write a program that prompts the user to enter an integer and checks if it’s positive, negative, or zero.
  • Use if, else if, and else statements along with appropriate output.

In the next lesson, we’ll explore more complex control structures including switch statements and loops in C. Practice writing and understanding conditional statements to enhance your programming skills.