Typedef keyword in c

// typedef is a keyword which is used to give name to the existing data type

// syntax- typedef <previous_name> <alias_name>;

#include <stdio.h>

int main()

{

    typedef int nt; // here i given a new name to the data type int to 'nt'

    nt a;           // now i can use 'nt' in place of int

    // it is not neccesary to use alias name or new name i can use previous name also like u can see below

    int b;

    //--------------------

    // using typedef with structure

    typedef struct library

    {

        char name[20];

        int pages;

        char author[20];

    } lib;            // here i given a new name to the data type library(structure) to 'lib'

    lib book1, book2; // here now i can use 'lib' instead of 'struct library'

    book1.pages = 100;

    printf("number of pages of the book:%d", book1.pages);

}