Conditional Statement in C

Conditional statements, also known as Selection statements, are control statements that allows a program to make decisions and execute certain blocks of code only when specific conditions are met.

• Conditional statements evaluate expressions (conditions) that return either true or false and perform actions based on these evaluations.

Types of Conditional Statements in C:

• The if Statement
• The if-else statement
• if-else if-else ladder
• switch statement
• Ternary (Conditional) Operator ?:

a.) The if Statement:

• The if statement is used to execute a block of code if a condition is true. If the condition is false, it is skipped.

Syntax:

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

Example:

#include <stdio.h>
int main() {
    int x = 10;

    if (x > 0) {
        printf("x is positive\n");
    }

    return 0;
}

2.) The if-else statement:

• The if-else statement allows you to execute one block of code if the condition is true and another block if the condition is false.

Syntax:

if (condition) {
    // True block
} else {
    // False block
}

Example:

#include <stdio.h>
int main() {
    int x = -5;

    if (x > 0) {
        printf("x is positive\n");
    } else {
        printf("x is not positive\n");
    }

    return 0;
}

3.) The if-else if-else Statement:

The if-else if-else statement is used when you have multiple conditions to check. It allows you to test multiple conditions and execute code based on the first true condition.

Syntax:

if (condition1) {
    // Block for condition1
} else if (condition2) {
    // Block for condition2

Example:

#include <stdio.h>
int main() {
    int x = 0;

    if (x > 0) {
        printf("x is positive\n");
    } else if (x == 0) {
        printf("x is zero\n");
    } else {
        printf("x is negative\n");
    }

    return 0;
}

4.) The switch Statement

The switch statement is a pattern-matching feature that allows for cleaner and more readable code for scenarios where multiple conditions need to be checked.

Syntax:

switch (expression) {
    case constant1:
        // code block
        break;
    case constant2:
        // code block
        break;
    default:
        // code block
}

Example:

#include <stdio.h>
int main() {
    int day = 2;

    switch (day) {
        case 1:
            printf("Monday\n");
            break;
        case 2:
            printf("Tuesday\n");
            break;
        case 3:
            printf("Wednesday\n");
            break;
        default:
            printf("Other day\n");
    }

    return 0;
}

Using if- else as Ternary Operator

In C, you can use an if-else statement in a compact form known as a ternary operator (or conditional expression). The ternary operator allows you to write a single line of code to evaluate a condition and return a value based on whether the condition is True or False.

Syntax of Ternary Operator:

condition ? value_if_true : value_if_false;

• condition: The expression to evaluate.
• value_if_true: The result if the condition is True.
• value_if_false: The result if the condition is False.

Example:

#include <stdio.h>
int main() {
    int age = 20;

    // Ternary operator
    const char* status = (age >= 18) ? "Adult" : "Minor";
    printf("%s\n", status);

    return 0;
}