Difference Between if-else and switch in C

In C programming both switch statements and if-else statements are used to perform decision-making and control the flow of the program according to predefined conditions. In this article, we will discuss the differences between the if-else and switch statements.

switch Statement

A control flow statement called a switch statement enables a program to compare an expression to a set of potential constant values by managing many scenarios according to the expression’s value. When handling several potential scenarios, the switch statement makes the code easier to comprehend and maintain.

Syntax of switch Statement

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

Example of switch Statement

The below example demonstrates the implementation of switch statement.

C

// C program to demonstrate the implementation of switch
// statement.
#include <stdio.h>
int main()
{
    int day = 3;
    switch (day) {
    case 1:
        printf("Monday\n");
        break;
    case 2:
        printf("Tuesday\n");
        break;
    case 3:
        printf("Wednesday\n");
        break;
    case 4:
        printf("Thursday\n");
        break;
    case 5:
        printf("Friday\n");
        break;
    case 6:
        printf("Saturday\n");
        break;
    case 7:
        printf("Sunday\n");
        break;
    default:
        printf("Invalid day\n");
    }
    return 0;
}

Output

Wednesday

if-else Statement

Conditional control structure called if-else statements are used to allow the execution of a particular code blocks on the basis that the given condition results in true of false. By running code in this way i.e. selectively according to whether a certain condition is true or false, we can easily make judgements.

Syntax of if-else Statement

if (condition) {
     //code
} 
else { 
     //code
}

Example of if-else

The below example demonstrates the implementation of if-else statement.

C

// C program to demonstrate the implementation of if-else
// statement.
#include <stdio.h>

int main()
{
    int number = 5;

    if (number > 0) {
        printf("The number %d is positive.\n", number);
    }
    else if (number < 0) {
        printf("The number %d is negative.\n", number);
    }
    else {
        printf("The number is zero.\n");
    }
    return 0;
}

Output

The number 5 is positive.

Difference Between if-else and switch Statement

The main differences between if-else and switch statement are listed in the following table:

S. No.	if-else Statement	switch Statement
1	The condition which used in if-else can be any Boolean expression.	The expression in switch is usually an integral type or an enumerated type.
2	It can handle multiple conditions using else if clauses.	Designed for evaluating a single expression against multiple constants.
3	if-else doesn’t have fall-through behavior by default.	switch can have fall-through behavior (case statements without breaks).
4	Optional else block for handling cases not explicitly covered.	Optional default case for handling cases not explicitly covered.
5	Suitable for complex, non-trivial conditions.	More concise for handling a series of conditions based on a single expression.

Difference Between if-else and switch in C – FAQs

What is the primary difference between switch and if-else statements in C?

The main distinction between them is how they manage conditional branching. Switch is meant for scenarios when we have a single expression with several possible constant values; if-else statements let we develop more intricate conditional structures.

When should I use a switch statement instead if-else statements?

When evaluating a single phrase against several constant values, use a switch statement. When working with several situations, this can help to make the code cleaner and easier to read. If your conditions need intricate logical statements, the if-else operator might be a better fit.

Are switch statements more efficient than if-else statements?

Generally speaking, there is very little efficiency difference between switch and if-else. Compilers frequently have the ability to efficiently optimise both constructs. Premature optimisation is not advised, so choose the one that improves the readability and maintainability of your code.

Are there any specific scenarios where using switch is strongly recommended?

Switch statement are frequently used for things like menu options or state transitions in finite state machines, when you have one variable to compare against several constant values.