STRINGSSTRINGS&&

STRING HANDLING FUNCTIONS STRING HANDLING FUNCTIONS

The char Data TypeThe char Data Type

Variables of type char take up typically one byte in memory and are used to store printable and non-printable characters. The ASCII code is used to associate each character with an integerFor example the ASCII code associates the character ‘m’ with the integer 109.

Internally, C treats character variables as integers.

ASCII CHARACTER SETASCII CHARACTER SET

WHAT ARE STRINGSWHAT ARE STRINGSIn C strings are represented as array of

charactersStrings ie character arrays are always terminated

by a null character(\0) at the end by default

Note\0 is used to identify the end of the stringASCII value of \0 is 0

Representation of strings in memoryRepresentation of strings in memory

The fig shows how the string “college” is represented in the computers memory

Declaring strings Declaring strings

Reading string inputsReading string inputs

Here the string is read with the help of a loop control character by character. This method is very rarely used The declaration char code[20] ;must be done earlier in the program

Reading string inputsReading string inputs

Here a single word is read. In case of multiple words separated by spaces only the first word is read. This method is used when we are sure that the inputs will not contain multiple words separated by spaces

Note:While scanning the ‘&’ symbol is not used as in other cases

Reading string inputsReading string inputs

The gets( ) is an inbuilt function available with <stdio.h> library. This function can read multiple words which are separated by spaces

Printing/displaying the stringsPrinting/displaying the strings

PROBLEM 1: Write a PROBLEM 1: Write a program to store the name program to store the name of a student and then of a student and then display the same display the same

PROBLEM 2: Write a program PROBLEM 2: Write a program to find the length of the to find the length of the name(without using string name(without using string function)function)

PROBLEM 3: Write a program PROBLEM 3: Write a program to check whether two strings to check whether two strings are equalare equal(without using string (without using string functions) functions)

PROBLEM 4: Write a program PROBLEM 4: Write a program to count the number of vowels to count the number of vowels in a string in a string

PROBLEM 4: Write a program PROBLEM 4: Write a program to count the number of to count the number of words in a string words in a string

Lot of string handling functions are available in the header file <string.h>

So whenever we want to make use of these inbuilt library functions in our program then we must include the string.h file

FUNCTIONS IN STRING.HFUNCTIONS IN STRING.H

SOME POPULAR ONESSOME POPULAR ONES

Examples of String Examples of String FunctionsFunctions

Here are some examples of string functions in action:

char s1[]="big sky country";char s2[]="blue moon";char s3[]="then falls Caesar";

Write a program to Write a program to compare two strings and compare two strings and to concatenate them if to concatenate them if they are unequalthey are unequal

PROBLEM 5: Write a PROBLEM 5: Write a program to check whether a program to check whether a given string is palindrome given string is palindrome or notor not

PROBLEM 2: Write a program PROBLEM 2: Write a program to sort a list of names in to sort a list of names in ascending order ascending order