Typedef in C – Easy Explanation | IIES Bangalore
- 1. www.iies.in PH: +91 98869 20008 enquiry@iies.in TYPEDEF IN C
- 2. www.iies.in PH: +91 98869 20008 enquiry@iies.in • Type aliases that enhance the readability and manageability of the code can be created with typedef. It can generate new identifiers for types that have been defined already. • Typedef is a user-defined datatype • The keyword is typedef • It is used to create your own datatype • Typedef has a lifetime and scope Syntax: typedef int ind; Typedef in C
- 3. www.iies.in PH: +91 98869 20008 enquiry@iies.in Basic Usage of typedef: The typedef keyword in C is used to create new names (aliases) for existing data types. This enhances readability and contributes to the code's maintainability. Example:
- 4. www.iies.in PH: +91 98869 20008 enquiry@iies.in typedef with Structures:
- 5. www.iies.in PH: +91 98869 20008 enquiry@iies.in typedef with Pointers:
- 6. www.iies.in PH: +91 98869 20008 enquiry@iies.in typedef with Arrays:
- 7. www.iies.in PH: +91 98869 20008 enquiry@iies.in typedef for Function Pointers:
- 8. www.iies.in PH: +91 98869 20008 enquiry@iies.in Predefined typedef Variables in C and C++ C and C++ have several predefined typedef types that provide alternative names for existing data types. These typedefs enhance the code's portability and readability. Standard Integer Types (stdint.h / cstdint) C99 introduced the <stdint.h> header, which defines fixed-width integer types using typedef. C++ includes this as <cstdint>.
- 9. www.iies.in PH: +91 98869 20008 enquiry@iies.in Typedef Equivalent Type Size int8_t signed char 1 byte uint8_t unsigned char 1 byte int16_t short int 2 bytes uint16_t unsigned short int 2 bytes int32_t Int 4 bytes uint32_t unsigned int 4 bytes int64_t long long int 8 bytes uint64_t unsigned long long int 8 bytes Common Typedefs for Integer Types
- 10. www.iies.in PH: +91 98869 20008 enquiry@iies.in Typedef Purpose size_t Used for sizes of objects (array indexing, malloc(), etc.) ptrdiff_t ptrdiff_t Holds the difference of two pointers wchar_t Represents wide characters Size-Specific Types (stddef.h) Some important typedef types from <stddef.h>:
- 11. www.iies.in PH: +91 98869 20008 enquiry@iies.in size_t is an unsigned integer type that represents the sizes of objects in memory. It is commonly used for array indexing, memory allocation, and loop counters. The actual size of size_t depends on the system architecture: 32-bit systems: size_t typically occupies 4 bytes (unsigned integer with a size of 32 bits). 64-bit systems: size_t typically occupies 8 bytes (unsigned integer of 64 bits). Example size_t in C:
- 12. www.iies.in PH: +91 98869 20008 enquiry@iies.in ptrdiff_t is a signed integer type defined in the C header. It serves to illustrate the variance between two pointers. Why Use ptrdiff_t? • It ensures portability across different systems. • It is specifically designed for pointer arithmetic. • It prevents issues that may arise from using standard integer types for pointer differences. Example ptrdiff_t in C: