Cpr Transperencies - Ch 04 Structures

Chapter no. 4 Functions and Structures

Structure ‹ In general, we can call a structure is a collection of different types of data. ‹ A Structure contains number of data types grouped together. These data types may be or may not be of same data type. C’s Implementation of Structure • The keyword ‘struct’ is used for creating a structure. Syntax:

struct structure-name { datatype1 varname1; datatype1 varname2; datatype1 varname3; }; creating the variables of structure: struct structure-name var1, var2, var3;

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Example:

struct list { int roll; char name[10]; float marks; };

Representation of structure: roll

Integer

name

Array of 10 characters

marks

Float

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Arrays vs Structures • An array is the collection of related data elements of same type. Structure can have elements in different types. • An array is derived data type, whereas a structure is programmer defined data type. • An array behaves like a built-in data type. All we have to do is to declare an array variable and use it. But, in case of a structure, first we have to design and declare data structure before the variables of that type are declared and used.

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Accessing Structure Members

struct list { int roll; char name[10]; float marks; }; struct list stu1, stu2; stu1.roll = 12; stu1.marks = 85.63; strcpy(stu1.name, “Ajay”); stu2.marks = 81.22; stu2.roll = 10; or scanf(“%s”, stu2.name); scanf(“%d”, &stu1.roll); scanf(“%f”, &stu2.marks);

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Valid declaration. struct list { int roll; char name[10]; float marks; }; struct list a , b , c; It is equivalent to : struct list { int roll; char name[10]; float marks; }

a, b, c;

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Structure Initialization

struct player { int matches, runs; char name[10]; float average; }; struct player p1, p2, p3; p1 = {120,3450,“Raj”,42.1}; p2 = {71,1492,“Ram”,35.81};

printf(“Average of %s is %f”, p1.name, p1.average);

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Example: Creating a student database of 3 students. void main( )

{ struct student { int roll; char name[10]; float marks; } a, b, c; printf(“Enter all information of students:” ); scanf(“%d %s %f”, &a.roll, a.name, &a.marks); scanf(“%d %s %f”, &b.roll, b.name, &b.marks); scanf(“%d %s %f”, &c.roll, c.name, &c.marks); printf(“You entered this information:”); printf(“\n%d %s %f”, a.roll, a.name, a.marks); printf(“\n%d %s %f”, b.roll, b.name, b.marks); printf(“\n%d %s %f”, c.roll, c.name, c.marks);

}

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By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Array of structures. void main( ) { struct student { int roll; char name[10]; float marks; } a[10]; int i; printf(“Enter info. of students: ”); for(i = 0 ; i < 10 ; i++) { scanf(“%d %s %f”, &a.roll[i], a.name[i], &a.marks[i]); } for(i = 0 ; i < 10 ; i++) { printf(“\n%d %s %f”, a.roll[i], a.name[i], a.marks[i]); } } -8-

By, Kute T. B. for CPR (FYIF) 2007-08

Chapter no. 4 Functions and Structures

Memory map for arrays.

a[i].roll

i

a[i].name a[i].marks

0 1 2

a[4].roll

3 4 5 6 7 8

a[6].name

9

a[9].marks

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By, Kute T. B. for CPR (FYIF) 2007-08