Typedef Declaration

Usage of typedef keyword in C++
cpp code

/* C typedef assigns a name to a type.  Its syntax can be really awful. */
#include <stdio.h>

/* Make fred an alias for the type name integer. */
typedef int fred;

/* Assign a type name to an enumeration. */
typedef enum { Sun, Mon, Tue, Wed, Thu, Fri, Sat} day;

int main()
{
        fred m = 5;
        day today = Fri;

        if(today == m) printf("Yes!\n");
        else printf("Nope.\n");
}

The typedef is the only way to create type names in plain C. It essentially aliases for types for other types. It still exists in C++, but is not used very often, since classes are usually used to create new types.