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Assignment 5: String Handling    Date : 12^th  Feb, 07

Do not use any standard string handling functions.

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Introduction:

Arrays:

An array is a variable that holds multiple values of the same type. Arrays can be created from any of the C data types like int, float, char,... The contents of an array can be accessed by its index value. In C, an array index starts from zero. The elements of the array occupy adjacent locations in memory.

The syntax for declaring an array is :

type name[size];

Character Arrays:

An array of characters should always terminated by the special null character ‘\0’. For example a string constant, such as "SPRING" is an array of characters. It is represented internally by the ASCII characters as

‘S’, ‘P’, ‘R’, ‘I’, ‘N’, ‘G’, ‘\0’.

 
A small example depicting the declaration of arrays is shown below.
 

#include<stdio.h>

   int main (void) {
 
  
  int i=0;
    
  int x[4],y[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};// declaring an integer array
 
  char Letter='x';
 
  char Letters[10] = {'c','h','a','r','a','c','t','e','r','\0'}; //declaration of a character array
 
  char Text[10]="character"; // alternative way of declaring a character array

 
  for(i=0;i<4;i++) 
  {
  scanf(“%d”,&x[i]);
  }
 
  for(i=0;i<4;i++) 
  {
  printf("\n The value of x[%d] is %d",i, x[i]);
  }
 
  printf("\n The value of y[0] is %d", y[0]);
 
  printf("\n The value of y[9] is %d", y[9]);
 
  printf(“\n The string Letters is %s and the string Text is %s ”, Letters,Text);
 
 }
 
INPUT:
 
 0,1,2,3.
 
OUTPUT:
 
 The value of x[0] is 0
 
 The value of x[1] is 1
 
 The value of x[2] is 2
 
 The value of x[3] is 3
 
 The value of y[0] is 1
 
 The value of y[9] is 10
 
 The string Letters is character and the string Text is character

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Tutorial 5A:

Write a C program to find the length of a given string.

Solution:

#include<stdio.h>

#define MAXLEN 100

int main(){

int i,length;

char str[MAXLEN];

printf(“Enter the input String.:”);

scanf(“%[^\n]s”,str);

for(i=0,length=0;str[i]!=’\0’;i++)

length++;

printf(“length of given String is %d”,length);

}

Example:

INPUT	OUTPUT
Hello World	11
!1234$	6

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Assign. 5A:

Write a C program to check whether given strings are identical or not.

INPUTS	OUTPUT
Computer, Computer	Equal
Programming, Programing	Not equal

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Tutorial 5B:

    Write a C program to concatenate two strings.

Solution:

#include<stdio.h>

#define MAXLEN 100

int main(){

int i,c;

char str1[MAXLEN],str2[MAXLEN],str3[MAXLEN];

printf(“Enter the first input String.:”);

scanf(“%[^\n]s”,str1);

printf(“Enter the second input String.:”);

scanf(“%[^\n]s”,str2);

for( i = 0 , c = 0 ; str1[i]!=’\0’ ; i++ )

{

str3[c] = str1[i];

c++;

}

for( i = 0 ; str2[i]!=’\0’ ; i++ )

{

str3[c] = str2[i];

c++;

}

str3[c]=’\0’;

printf(“Concatenated String is :%s”,str3);

}

Example:

INPUTS	OUTPUT
Compute, r	Computer
Prog ram, ming	Prog ramming

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Assignment 5B:

Write a C program to extract a particular portion of a string. The positions (starting and ending) of extraction will be given as inputs.

INPUTS	OUTPUT
Computer, 3, 5	mpu
Programming, 1, 21	Invalid input

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Tutorial 5C:

    Write a C program to replace a particular character in a string with a given character.

Solution:

#include<stdio.h>

#include<stdlib.h>

#define MAXLEN 100

int main(){

int i;

char c,d,str[MAXLEN];

printf(“Enter the first input String.:”);

scanf(“%[^\n]s”,str);

printf(“Enter the character to be replaced.:”);

scanf(“%c”,&c);

printf(“Enter the character with which to be replaced.:”);

flushall();

scanf(“%c”,&d);

for( i = 0 ; str[i]!=’\0’ ; i++ )

{

if( str[i] == c)

str[i] = d;

}

printf(“Resultant String is :%s”,str);

}

INPUTS	OUTPUT
Cartoon, o, a	Cartaan
Programming, g, k	Prokrammink

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Assign 5C:

Write a C program to remove a particular character in a string.

INPUTS	OUTPUT
Computer, p	Comuter
Programming, m	Prograing

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Assign. 5D:

    Write a C program to check whether a given word is palindrome or not.

Ex: MALAYALAM, ANNA, AMANAPLANACANALPANAMA…

Hint: A word is said to be palindrome if it reads the same backward or forward.