Array and string

Dr. S. & S.S. Gandhy Government College of Engineering and Technology

SEM:- 1ST

SUBJECT:- COMPUTER PROGRAMMING AND UTILIZATIONTOPIC:- ARRAY AND STRINGSTUDENT’S NAME:-PRATIK B. PATEL PRASHANT A. CHELANIVIJAY D. VADHERNIKHIL R. PATIL

ARRAY :- NEED OF ARRAY ARRAY CONCEPT DECLARATION OF ONE-

DIMENTIONAL ARRAY INITIALIZATION OF ONE-

DIMENTIONAL ARRAY MULTYDIMENSIONAL ARRAY

NEED OF ARRAY: It is very difficult to write a program

in ‘C’ which consisting large data items like addition of 50 integers, marks of student in University, etc.

‘C’ program provides a solution called ‘ARRAY’.

By using array, it is easy to include large numbers of data items.

ARRAY CONCEPT:- An array is a group of data items of the

same data type that share a common name.

An array should be of same datatype and consists of integers or strings and so on.

An array is linear and homogeneous. An array stores the data elements in

sequential order. Homogeneous means all data items are of

same datatype.

Elements of array are specifying a subscript.

A subscript is also called index. Subscipt is start from 0 and cannot

negative. There are two types of array. 1). One-dimentional arrays(also called

vectors) 2). Multi-dimentional arrays(also called

Matrix)

DECLARATION OF ONE-DIMENTIONAL ARRAY:- Syntex: datatype arrayname[size] Where, datatype:- The type of the data stored in

the array Arrayname:- Name of the array Size:- Maximum number of elements an

array can hold Example:- int marks[10]

Mark[0] Mark[1] ………….. ……….....

Mark[9]

INITIALIZATION OF ONE-DIMENTIONAL ARRAY Int mark[6]={3,7,8,4,5,6} Is also equel to Int mark[]={3,7,8,4,5,6} It will occupy in memory like,

a[0] a[1] a[2] a[3] a[4] a[5] Char a[8]={‘L’,’E’,’A’,’R’,’N’,’’,’C’}

a[0] a[1] a[2] a[3] a[4] a[5] a[6] a[7] When compiler sees a character array, it add a null

character.So, while declaring a character array, we must allow one extra element space for null character.

3 7 8 4 5 6

‘L’ ‘E’ ‘A’ ‘R’ ‘N’ ‘’ ‘C’ ‘\0’

MULTYDIMENSIONAL ARRAY If an array have more than one dimension, is called

multi-dimensional array. Two dimensional array have two subscript, three

dimensional array have three subscript. Declaration of two dimensional array:- Int a[2][3] It consist of two rows and three colomns. a[0][0] a[0][1] a[0][2] a[1][0] a[1][1] a[1][2]

1 2 3 4 5 6

PROGRAM OF SIMPLE ARRAY

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Program to reverse a array

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Strings INTRODUCTION INITIALIZING STRING VARIABLES READING AND DISPLAYING STRINGS STRING HANDLING FUNCTIONS PROGRAMS OF STRING

INTRODUCTION :- Strings are array of characters i.e. they are

characters arranged one after another in memory. Thus, a character array is called string.

Each character within the string is stored within one element of the array successively.

A string is always terminated by a null character (i.e. slash zero \0).

A string variable is declared as an array of characters.

Syntax:char string_name[size];

E.g. char name[20]; When the compiler assigns a character

string to a character array, it automatically supplies a null character (‘\0’) at the end of the string

Initializing String Variables

Strings are initialized in either of the following two forms:char name[4]={‘R’,‘A’,‘M’, ‘\0’};char name[]={‘R’,‘A’,‘M’, ‘\0’};

ORchar name[4]=“RAM”;char name[]=“RAM”;

When we initialize a character array by listing its elements, the null terminator or the size of the array must be provided explicitly.

R A M \0name[0

]name[1

]name[2] name[3

]

Reading and displaying Strings

It can be done manually.Using printf() and scanf().Using gets() and puts().

Using printf() and scanf()

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Using gets() and puts()

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String handling functions

strcpy ( ) Copies str2 into str1strlen ( ) Gives the length of str1strcmp ( ) Returns 0 if str1 is same as

str2. Returns <0 if strl < str2. Returns >0 if str1 > str2

strcmpi ( ) Same as strcmp() function. But, this function negotiates case.  “A” and “a” are treated as same.

strdup ( ) Duplicates the stringstrlwr ( ) Converts string to

lowercasestrupr ( ) Converts string to

uppercasestrrev ( ) Reverses the given string

Program to find string length using function

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Program to Reverse string using function

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DIFFERECE BETWEEN ARRAY AND STRINGARRAY STRINGAn array can hold any data type.

String can hold only char data

An array size can not be changed.

A string size can be changed if it is a char pointer

The last element of an array is an element of the specific type.

The last character of a string is a null – ‘\0’ character.

The length of an array is to specified in [] at the time of declaration (except char[]).

The length of the string is the number of characters + one (null character).