Type Casting in C


Type casting, also known as type conversion, is the process of converting one data type into another in C. It allows you to work with different data types and perform operations that might not be allowed by default. In this guide, we'll explore the concepts of type casting in C and provide sample code to illustrate its usage.

Implicit vs. Explicit Type Casting

In C, type casting can be categorized into two main types:

  • Implicit Type Casting: Also known as "type promotion," this type of casting is performed automatically by the compiler. It promotes a lower data type to a higher data type to avoid data loss. For example, converting an integer to a floating-point number during a calculation.
  • Explicit Type Casting: This type of casting is initiated by the programmer using casting operators. It allows you to forcefully change the data type of a value when required.

Explicit Type Casting Operators

C provides several casting operators to perform explicit type casting:

  • (type)
    This is the most common casting operator, where
    represents the target data type. For example,
    , or
  • sizeof
    It can be used to find the size of a data type and is often used in casting for memory allocation.
  • _Static_assert
    It is used to check whether a constant expression is true at compile time.

Sample Code

Let's explore some examples of type casting in C:

Implicit Type Casting

#include <stdio.h>
int main() {
int num1 = 10;
double num2 = 5.5;
double result = num1 + num2; // Implicit type casting from int to double
printf("Result: %lf\\n", result);
return 0;

Explicit Type Casting

#include <stdio.h>
int main() {
double num1 = 10.5;
int num2;
num2 = (int)num1; // Explicit type casting from double to int
printf("Result: %d\\n", num2);
return 0;

Using the

#include <stdio.h>
int main() {
int num1 = 42;
float num2;
num2 = (float)num1 / sizeof(int); // Explicit type casting using the sizeof operator
printf("Result: %f\\n", num2);
return 0;


Type casting is a crucial aspect of C programming that allows you to work with different data types and handle data conversions. This guide has introduced you to the concepts of implicit and explicit type casting, along with the casting operators available in C. Sample code demonstrates the usage of type casting. As you continue your C programming journey, you'll find type casting to be a valuable tool for data manipulation and compatibility.