C Language, What the difference between "typedef struct" and "typedef struct tag

What the difference between "typedef struct" and "typedef struct tag_Struct"?

Author	Message
Brya #1 / 3	What the difference between "typedef struct" and "typedef struct tag_Struct"? HI: There are two style to define a new data type,one is typedef struct { int a; int b; Quote: }TMail; the other is typedef struct tag_Struct { int a; int b; Quote: }TMail; What the diffenerce? Thank you! Sincerely, Bryan
Fri, 11 Feb 2005 16:26:45 GMT

Joona I Palast #2 / 3	What the difference between "typedef struct" and "typedef struct tag_Struct"? Quote: > HI: > There are two style to define a new data type,one is > typedef struct > { > int a; > int b; > }TMail; > the other is > typedef struct tag_Struct > { > int a; > int b; > }TMail; > What the diffenerce? > Thank you! The only difference is that in the first code sample, you're creating the name "TMail" as an alias to an unnamed structure, while in the second sample, you're creating the name "TMail" as an alias to a structure named "struct tag_Struct". Despite its name, typedef does not create new types. It creates new names for already existing types. In your first code sample, the already existing type doesn't have a name yet, but in your second sample, its name is "struct tag_Struct". What does this mean in practice? In your first example you can only refer to your structure type as "TMail". In your second one, you can refer to it either as "TMail" or "struct tag_Struct". -- \| Kingpriest of "The Flying Lemon Tree" G++ FR FW+ M- #108 D+ ADA N+++\| \| http://www.helsinki.fi/~palaste W++ B OP+ \| \----------------------------------------- Finland rules! ------------/ "Shh! The maestro is decomposing!" - Gary Larson
Fri, 11 Feb 2005 16:30:37 GMT

Malcol #3 / 3	What the difference between "typedef struct" and "typedef struct tag_Struct"? Quote: > The only difference is that in the first code sample, you're creating > the name "TMail" as an alias to an unnamed structure, while in the > second sample, you're creating the name "TMail" as an alias to a > structure named "struct tag_Struct". Generally you don't need the tag, unless the structure contains a pointer to another structure of the same type eg typedef struct Node_tag; { struct Node_tag parent; struct Node_tag sib; struct Node_tag *child; int data; Quote: } Node;
Sat, 12 Feb 2005 04:39:13 GMT

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