Definition, Declaration of Structures in C.pptx

Structures are a way to group several related variables into one place. Each variable in the structure is known as a member of the structure.

1. V.V. Vanniaperumal college for women Programming in C Structures Dr. T. Anitha Assistant Professor Department of Mathematics(SF)

2. int dynami ; int trig; int c; float lab;

3. An array is a fixed-size sequenced collection of elements of same data type. ie ., it is a grouping of like-type. So in array a list of items can be given in one variable name. The general form of array declaration is type variable_name [size] Examples: int dynami [50]; int trig[50]; int c[50]; float lab[40]; Array

4. Example: Suppose we have to store prices of three different items in four shops: Item 1 Item 2 Item 3 Shop 1 310 275 365 Shop 2 210 190 325 Shop 3 405 225 240 Shop4 260 300 380

5. C allows as to define such tables of item in single variable using two-dimensional arrays such as p[4][3] Two-dimensional array are declared as follows: Type array_name [ row_size ][ column_size ]

6. Structure is a mechanism for packing data of different data type. A structure is a convenient tool for handling a group of related data item. E xample: Using structure we can represent a set of attributes, such as student_name , roll_number and marks. Structures in C

7. struct book_bank { char title[20]; char author[15]; int page; Float price; }; Definition of Structures

8. T he keyword struct declares a structure to hold the details of four data field, namely title, author, pages and price, these fields are called structure elements or members . Note that each member may belong to different data types. book-bank is the name of the structure which called structure tag .

9. s truct tag_name { d ata_type member1; data_type member2; data_type member; --------- }; The general format of structure definition

10. Declaring Structure Variables After defining a structure we can declare variables of that type. A structure variable declarations is similar to declaration of variables of any other data types. It includes the following elements: The keyword strut The structure tag name. List of variable names separated by commas. A terminating semicolon. Example: struct book_bank , book1, book2, book3; It declares book1, book2, book3 are variables of type struct book_bank .

11. Declaring Structure Variables The complete variable definition and declaration is struct book_bank { char title[20]; char author[15]; int page; Float price; }; struct book_bank , book1, book2, book3;

12. Declaring Structure Variables It is also allowed to combine both variable definition and variable declaration in one step as: struct book_bank { char title[20]; char author[15]; int page; float price; } book1, book2, book3;

13. Access Structure Members To access members of a structure, use the member operator dot operator (.): Example: book1.price is the variable representing the price of book1 and it is treated like any other ordinary variable.

14. Assigning values to the Structure variables b ook.page =250; book1.price=120.5 Strcpy (book1.title,”Algebra”); Strcpy (book1.author, “ Arumugam ”);

15. Assigning values to the Structure variables Reading data from keyboard We can use scanf to give the values through the keyboard Scanf (“%s\n”,&book1.title); Scanf (“%d\n”, &book1.pages);

16. Example Program struct personal { char name[20]; int day; char month[10]; float salary; }; m ain() { structure personal person; printf (“Input Values\n”); scanf (“%s %d %s %f”, person.name,&person.day , & person.month,&person.salary ); printf (“Output Values\n”); printf (“%s %d %s % f”, person.name,person.day , person.month,person.salary ); }

17. Output: Input Values Rani 10 January 25000 Output Values Rani 10 January 25000

18. Thank you