typedef in C Programming

"typedef" is a keyword,which is used to give a new name of datatype.

typedef datatype name;

here,"datatype" like int, float, struct, array etc and,"name" contains new name of datatype.

#include<stdio.h>
int main()
{
    typedef int num;
    num n;
    scanf("%d",&n);
    printf("%d",n);
    return 0;
}

Here the new name of 'int' is num.

Note:- It is mainly used with user defined datatype like(structure,union,enumration).

typedef used with structure

#include<stdio.h>
#include<string.h>
typedef struct student {
    char name[50];
    int roll_no;
    char subject[15];
    float percentage;
} STUDENT;
int main( ) {
    STUDENT st1;
    strcpy(st1.name, "Vikas kumar");
	strcpy(st1.subject, "C Programming");
    st1.roll_no=183481361;
    st1.percentage=76;
    printf( "Name : %s\n", st1.name);
    printf( "Roll No : %d\n", st1.roll_no);
    printf( "Subject : %s\n", st1.subject);
    printf( "Percentage: %f\n", st1.percentage);
    return 0;
}