TutorialsPoint
tutorialspoint.com › cprogramming › c_typedef.htm
Typedef in C
The C programming language provides a keyword called typedef to set an alternate name to an existing data type. The typedef keyword in C is very useful in assigning a convenient alias to a built-in data type as well as any derived data type ...
GeeksforGeeks
geeksforgeeks.org › c language › typedef-in-c
C typedef - GeeksforGeeks
July 23, 2025 - The C typedef keyword is used to redefine the name of already existing data types. When names of datatypes become difficult to use in programs, typedef is used with user-defined datatypes, which behave similarly to defining an alias for commands.
c - What is the use of typedef? - Stack Overflow
It's a bit of a misnomer: typedef does not define new types as the new types are interchangeable with the underlying type. Typedefs are often used for clarity and portability in interface definitions when the underlying type is subject to change or is not of importance. More on stackoverflow.com
How do I hide the implementation of a struct in the header file?
This is called an opaque type, and you've used one if you've ever used a FILE *. In the header you can do just as you suggested, typedef struct Punto Punto; which tells the compiler that there is a struct type called Punto. However, code that uses this header can only ever have a pointer to a Punto. You can't do Punto p;, for example, you can only ever do Punto *p;. In the C files where you have to deal with this type, you need the full definition of the struct. This is not a very reasonable solution for such a small type, though. If you're just making a point type that you want only accessed through functions, then do a normal struct definition and rely on the user to use it correctly. An opaque struct is generally inefficient and should only be used when necessary. You could also use private members to remind the user that the members should not be touched. C doesn't have true private members, so private members will need to be marked in some way and the users of the struct just have to know not to access them. typedef struct Punto { float _private_x; float _private_y; } Punto; More on reddit.com
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January 25, 2024Whats the difference between a normal struct and a typedef struct?
A struct that isn't typedef'd requires you to use the keyword struct every time you use it as a type (so it'd be struct MyStruct mystruct;). This doesn't apply for structs you typedef. More on reddit.com
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February 20, 2022Obvious reasons *not* to typedef a struct...?
Probably the most obvious reason not to typedef is to avoid hiding the fact that the object might be expensive to copy (i.e. is not actually a primitive type). A second, perhaps arguably less obvious reason, is lack of necessity. That is, the programmer is perfectly capable of writing struct foo and there is no particular reason to obscure the fact that foo is a struct, hence the need for a typedef isn't compelling. In the absence of necessity then, do the simple thing. More on reddit.com
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June 27, 2021Videos
03:33
C typedef 📛 - YouTube
05:03
Learn typedef in 5 minutes! 📛 - YouTube
05:26
C++ Typedef and type aliases explained 🙋♂️ - YouTube
06:40
Simple C - Using typedef and struct - YouTube
typedef Basics | C Programming Tutorial
17:05
C++ Tutorial: typedefs // how to use typedef to create synonyms ...
Wikipedia
en.wikipedia.org › wiki › Typedef
typedef - Wikipedia
3 weeks ago - typedef is a reserved keyword in the programming languages C, C++, and Objective-C. It is used to create an additional name (alias) for another data type, but does not create a new type, except in the obscure case of a qualified typedef of an array type where the typedef qualifiers are transferred ...
TechVidvan
techvidvan.com › tutorials › c-typedef-with-examples
C Typedef with Examples - TechVidvan
August 11, 2021 - Learn about C typedef with examples. It is a predefined keyword that helps in creating user-defined name for an existing data type.
W3Schools
w3schools.com › c › c_typedef.php
C typedef
C Examples C Real-Life Examples C Exercises C Quiz C Code Challenges C Practice Problems C Compiler C Syllabus C Study Plan C Interview Q&A ... The typedef keyword lets you create a new name (an alias) for an existing type.
GNU
gnu.org › software › c-intro-and-ref › manual › html_node › Defining-Typedef-Names.html
Defining Typedef Names (GNU C Language Manual)
You can define a data type keyword as an alias for any type, and then use the alias syntactically like a built-in type keyword such as int. You do this using typedef, so these aliases are also called typedef names.
cppreference.com
en.cppreference.com › cpp › language › typedef
typedef specifier - cppreference.com
Every identifier introduced in this declaration becomes a typedef name, which is a synonym for the type of the object or function that it would become if the keyword typedef were removed. The typedef names are aliases for existing types, and are not declarations of new types. typedef cannot be used to change the meaning of an existing type name (including a typedef name).
Top answer 1 of 8
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typedef is for defining something as a type. For instance:
typedef struct {
int a;
int b;
} THINGY;
...defines THINGY as the given struct. That way, you can use it like this:
THINGY t;
...rather than:
struct _THINGY_STRUCT {
int a;
int b;
};
struct _THINGY_STRUCT t;
...which is a bit more verbose. typedefs can make some things dramatically clearer, specially pointers to functions.
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From wikipedia:
typedef is a keyword in the C and C++ programming languages. The purpose of typedef is to assign alternative names to existing types, most often those whose standard declaration is cumbersome, potentially confusing, or likely to vary from one implementation to another.
And:
K&R states that there are two reasons for using a typedef. First, it provides a means to make a program more portable. Instead of having to change a type everywhere it appears throughout the program's source files, only a single typedef statement needs to be changed. Second, a typedef can make a complex declaration easier to understand.
And an argument against:
He (Greg K.H.) argues that this practice not only unnecessarily obfuscates code, it can also cause programmers to accidentally misuse large structures thinking them to be simple types.
Unstop
unstop.com › home › blog › typedef in c | usage with mulitple data types (+examples)
Typedef In C | Usage With Mulitple Data Types (+Examples)
May 15, 2024 - Typedef in C is a reserved keyword used to create an alias/ new name for existing data types. The primary purpose is to simplify complex type declarations in code.
Microsoft Learn
learn.microsoft.com › en-us › cpp › c-language › typedef-declarations
Typedef Declarations | Microsoft Learn
August 11, 2025 - A typedef declaration doesn't create new types. It creates synonyms for existing types, or names for types that could be specified in other ways. When a typedef name is used as a type specifier, it can be combined with certain type specifiers, but not others.
W3Schools
w3schools.in › c-programming › typedef
C typedef - W3Schools
typedef is a C keyword implemented to tell the compiler to assign alternative names to C's pre-existing data types. This keyword, typedef, is typically used with user-defined data types if the names of the datatypes become a bit convoluted or complicated for the programmer to obtain or use ...
Javatpoint
javatpoint.com › typedef-in-c
Typedef in C - javatpoint
Typedef in C with programming examples for beginners and professionals covering concepts, control statements, c array, c pointers, c structures, c union, c strings and more.
Educative
educative.io › blog › how-to-use-the-typedef-struct-in-c
How to use the typedef struct in C
May 19, 2025 - This combines the definition of the structure and the creation of the alias Point in a single statement. ... Define struct using typedef keyword.
GeeksforGeeks
geeksforgeeks.org › c language › typedef-versus-define-c
Difference between typedef and #define in C - GeeksforGeeks
January 2, 2025 - The typedef keyword is used to define a new type name for an existing type. It is used primarily to improve code readability by providing a more meaningful or simplified name for complex data types.
Learn C
learnc.net › home › learn c programming › c typedef
C typedef
April 13, 2025 - Summary: in this tutorial, you will learn how to create a new name for existing types using C typedef. The typedef keyword helps you simplify the complex declaration and makes your code more portable. C language provides the typedef keyword to assign new names for existing types. Literally, ...
PrepBytes
prepbytes.com › home › c programming › typedef in c
typedef in C
January 16, 2024 - In C, typedef is a keyword that allows users to create aliases for existing data types. This can make code easier to read and understand.
cppreference.com
en.cppreference.com › c › language › typedef
Typedef declaration - cppreference.com
The typedef declaration provides a way to declare an identifier as a type alias, to be used to replace a possibly complex type name · The keyword typedef is used in a declaration, in the grammatical position of a storage-class specifier, except that it does not affect storage or linkage:
Medium
medium.com › @Dev_Frank › typedef-dc45fa2a0794
Typedef. Typedef is a keyword used to create an… | by Dev Frank | Medium
May 22, 2024 - Typedef is a keyword used to create an alias for an existing data type. It simply means typedef declaration allows you to create custom type names that can replace type specifiers like int , float, and double. It does not allocate any storage.
Florida State University
cs.fsu.edu › ~myers › cgs3408 › notes › typedef.html
typedefs
Can use to create a shorter or more intuitive type name · Can be used to make code more modifiable (similar to the use of const variables · Soemtimes used to help make code more portable (across different systems, which may use different sizes for their common types). typedef <existing type name or definition> <new type name>;
guvi.in
studytonight.com › c › typedef.php
typedef Keyword in C Programming
Explore, upskill, and make each step count—exciting possibilities awaits! Our team will reach you out within the next 24 hours.Explore all Programs ... typedef is a keyword used in C language to assign alternative names to existing datatypes.