String Manipulations :

String in C language :

In C language, an array of characters is known as a string. Consider the following example to declare a string :

char st[50]

This statement declares a strings array with 50 characters. The control character '\0' which represents a null character is placed automatically at the end of any string used.

Example :

char name[5] = {'A', 'y', 'a', 'N', '\0'};

String handling functions :

There are four important string handling functions in C Language.

  1. strlen() function
  2. strcpy() function
  3. strcat() function
  4. strcmp() function

strlen() function :

strlen() function is used to find the length of a character string.

Syntax :

  1. int n;
  2. char st[20]="Bangalore";
  3. n = strlen(st);

This will return length of the string 9 which is assigned to an integer variable n.
Note : That the null character '\0' available at the end of a string is not counted.

strcpy() function :

strcpy() function is used to copy a character variable.

Syntax :

  1. char city[15];
  2. strcpy(city,"BANGALORE")

This will assign the string "BANGALORE" to the character variable city.
Note : That character value like city = "BANGALORE"; cannot be assign in C language.

strcat() function :

strcat() function is used to join character stings. When two character strings are joined, it is referred as concatenation of strings.

Syntax :

  1. char city[20]="BERHAMPORE";
  2. char pin[8]="742103";
  3. strcat(city,pin);

This will join the two strings and store the result in city as "BERHAMPORE742103".
Note : That the resultant string is always stored in the left side string variables.

strcmp() function :

strcmp() function is used to compare two character strings.

Syntax :

  1. char city[20]="MADRAS";
  2. char town[20]="MANGALORE";
  3. strcmp(city,town);

This will return an integer value - 10 which is the difference in the ASCII values of the first mismatching letters 'B' and 'N'.
Note : That the integer value obtained as the difference may be assigned to an integer variable as follows :

int n;
n = strcmp(city,town);

<string.h> :

<string.h> is header in the C standard library for the C language which help us for handling string functions and memory functions.

Example :

  1. /* Description: write a program to use string functions */
  2. #include<stdio.h>
  3. #include<strings.h>
  4. main()
  5. {
  6. int n;
  7. char name[20],age[20],temp[20],verify[5]="AyaN";
  8. puts("Enter verified user Name : ");
  9. gets(name);
  10. puts("Enter verified user Age : ");
  11. gets(age);
  12. n = strlen(name);
  13. printf("\nName Length is - %d character.\n",n);
  14. strcpy(temp,name);
  15. puts(temp);
  16. puts("Name Copy Completed.\n");
  17. strcat(name,age);
  18. puts(name);
  19. puts("Name and age join completed.\n");
  20. if(strcmp(verify,temp)=='\0')
  21. {
  22. puts(name);
  23. puts("This user is verified.");
  24. }
  25. else
  26. {
  27. puts(name);
  28. puts("This user is not verified.");
  29. }
  30. getch();
  31. }

Note : gets() use for read strings (Data input) and puts() use for write strings (Data output).

Output :

c language - write a program to use string functions

Computer Science Engineering

Special Notes

It's a special area where you can find special questions and answers for CSE students or IT professionals. Also, In this section, we try to explain a topic in a very deep way.

CSE Notes