1) String initialization can be carried out in the following ways, similar to that of an array :

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1 Strings in C : Overview : String data type is not supported in C Programming. String is essentially a collection of characters to form particular word. String is useful whenever we accept name of the person, address of the person, some descriptive information. We cannot declare strings using string data type in C since there is no such data type available in C. Instead, an array of type character is used to represent a string. Normally a group of alphabets enclosed with in double quotes is a string literal in C. Description : Strings in C are generally represented by an arrays of characters. The end of the string is marked using a special character, the null character, which is simply the character with the value 0. (The null character has no relation except in name to the null pointer. In the ASCII character set, the null character is named NULL.) It is simply used to denote the end of the string. So all the rules applicable to array is applicable to strings Initialization of a string: 1) String initialization can be carried out in the following ways, similar to that of an array : The following declaration and initialization creates a string containing the word "Sourcelens". To hold the null character at the end of the array, the size of the character array containing the string is one more than the number of characters in the word "Sourcelens". char Name[11] = {'S', 'o', 'u', 'r', 'c', 'e', 'l', 'e', 'n','s','\0'}; 2) If a string is initialized similar to an array, then the above statement can be rewritten as follows : char Name[11]="Sourcelens"; In this case, it is not necessary to place the null character at the end of a string constant. The C compiler automatically places the '\0' at the end of the string when it initializes the array. 3) Another way to initialize a string is a variation of the above initialization where the size of the array does not have to be specified. char Name[]="Sourcelens"; When we declare char as string[], memory space will be allocated as per the requirement during execution of the program Library functions for string manipulation : The string.h header file contains various functions for manipulating arrays of characters.some of the string functions available are :

2 String Function strcpy() strcmp() strcat() strlen() strrev() Description String copy function which copies the contents of the source string to the destination string. String comparison function which compares two strings, string1 and string2 and returns a value =0, if string1 = string2 >0, if string1 < string2. <0, if string1 > string2. Concatenates or joins two strings. String function to find the number of characters in a string. String function to reverse the contents of a given string Array of Strings : Another common application of two dimensional arrays is to store an array of strings. A string is an array of characters; so, an array of strings is an array of arrays of characters. Of course, the maximum size is the same for all the strings stored in a two dimensional array. It is possible to declare a two dimensional character array of MAX strings of size SIZE as follows: char Name[MAX][SIZE]; Now, Name is a character array of size MAX * SIZE is created which can store MAX strings of SIZE size each. Figure 11.1

3 The above figure 11.1 shows a program to initialize a character array with a string and the print the individual characters in the array along with their position in the array. Figure 11.2 The above figure 11.1 shows a program to which denotes the functionalities of the library string functions such as strcpy(), strcat() and the strcmp() functions respectively. The strcpy() function copies the contents of the source (second argument ) to the destination array(first argument i.e array name). The strcat() function concatenates the content of the second argument with the first argument and the strcmp() function performs a character by character comparison of the two strings given as input.

4 Figure 11.3 The above figure 11.3 shows an example to sort an array of 5 strings using the bubble sort technique. The program shows the transition of the first iteration in the watch window. Since the first string in the array is greater than the second string, we use a temporary variable to swap the two values after comparing the two strings using the strcmp() function. Figure 11.4

5 The above figure 11.4 shows an output of the sorting function which sorts the given list of strings in the two dimensional array in the alphabetical order as seen in the watch window. The given array of strings are sorted with the help of a temporary character array and the bubble sort technique is implemented for sorting UNICODE : Not all the language has 26 letters. Some languages like Japanese or Chinese have 1000s of characters and so 256 numbers are not enough to represent all of them. All the strings seen so far are character arrays or arrays of numbers of size 8 bits. ( 1 byte ). 8 bit can only hold up to 2^8 values which is 256 values. So a 16 bit scheme came in to being called UNICODE. It is the modern way to represent strings. All major OS, programming languages, support and recommend Unicode instead of 1 byte char including C.