C Strings:-

In C language a string is group of characters (or) array of characters, which is terminated by delimiter \0 (null). Thus, C uses variable-length delimited strings in programs.

Declaring Strings:-

C does not support string as a data type. It allows us to represent strings as character arrays. In C, a string variable is any valid C variable name and is always declared as an array of characters.

Syntax:- char string name[size];

The size determines the number of characters in the string name.

Ex:- char city[10];

char name[30];

Initializing strings:-

There are several methods to initialize values for string variables.

Ex: - char city [8] = “NEWYORK”;

char city [8] = {“N”,“E”,“W”,“Y”,“O”,“R”,“K”,“/0”};

The string city size is 8 but it contains 7 characters, and one-character space is for the NULL terminator.

Storing strings in memory: -

In C a string is stored in an array of characters and terminated by \0 (null).

A string is stored in an array, the name of the string is a pointer to the beginning of the string. The character requires only one memory location.

If we use a one-character string it requires two locations. The difference is shown below,

The difference between array and string is shown below because strings are the variable-length structure, we must provide enough room for maximum length string to store and one byte for the delimiter.

Why do we need null?

A string is not a datatype but a data structure. String implementation is logical, not physical. The physical structure is an array in which the string is stored. The string is variable-length, so we need to identify the logical end of data in that physical structure.

string constant (or) Literal:-

A string constant is a sequence of characters enclosed in double-quotes. When string constants are used in the C program, it automatically initializes a null at end of the string.

Ex:- “Hello”     “Welcome”      “Welcome to C Lab”