Conditional Statements in C

Conditional Statements

Conditional statements are used to perform different actions based on different conditions. Very often when you write code, you want to perform different actions for different decisions.

In C programming we have the following conditional statements:

1. If statement
2. If else statement
3. If else if statement
4. Nested If statement

• Use if to specify a block of code to be executed, if a specified condition is true
• Use else to specify a block of code to be executed, if the same condition is false
• Use else if to specify a new condition to test, if the first condition is false

The if Statement

Use the if statement to specify a block of C code to be executed if a condition is true.

Syntax

if (condition) {

// block of code to be executed if the condition is true

}

Example: -

#include <stdio.h>
int main() {
    int marks = 75;

    if (marks >= 50) {
        printf("You passed the exam!");
    }
    
    return 0;
}

Output: You passed the exam!

The else Statement

Use the else statement to specify a block of code to be executed if the condition is false.

Syntax -

if (condition) {

// block of code to be executed if the condition is true

}

else {

// block of code to be executed if the condition is false

}

Example :-

#include <stdio.h>

int main() {
    int age = 16;

    if (age >= 18) {
        printf("Eligible to vote.");
    } else {
        printf("Not eligible to vote.");
    }
    
    return 0;
}

 Output: Not eligible to vote.

The else if Statement

Use the else if statement to specify a new condition if the first condition is false.

Syntax

if (condition1) {

// block of code to be executed if condition1 is true

}

else if (condition2) {

// block of code to be executed if the condition1 is false and condition2 is true

}

else {

// block of code to be executed if the condition1 is false and condition2 is false

}

Example:-

#include <stdio.h>
int main() {
    int marks = 72;

    if (marks >= 90) {
        printf("Grade: A\n");
    } else if (marks >= 75) {
        printf("Grade: B\n");
    } else if (marks >= 60) {
        printf("Grade: C\n");
    } else {
        printf("Grade: F\n");
    }
    
    return 0;
}

Output: Grade: C