Introduction

A string is a sequence of characters that is treated as a single data item. We have used strings in a number of examples in a number of example in the past. Any group of characters (except double quote sign) defined between double quotation marks is a string constant. Example: "Man is obviously made to think."

1. List of temperatures recorded every hour in a day, or a month, or a year
2. List of employees in an organization.
3. List of products and their cost sold by a store.
4. Table of daily rainfall data and so on.

Character  strings are often used to build meaningful and readable programs. The common operations performed on character string include:

1. Reading and writing strings
2. Combining string together
3. Copying one string to another
4. Comparing string for equality
5. Extracting a portion of a string

In this chapter we shall discuss these operations in detail and examine library function that implement them.

Declaring and Initializing String Variable

C does not support strings as a data type. However, it allows us to represent string as character arrays. in c therefore, a string variable is any valid variable name and is always declared as an array of characters. The general form of declaration of a string variable is.
  The size determine the number of characters in the string.... name. Some examples are:


Like numeric arrays, character arrays may be initialized when they are declared C permits a character array to be initialized in either of the following two forms

This will result in a compile time error. Also note that we cannot separate the initialization from declaration. This is

is not allowed. Similarly,

is not allowed. An array name cannot be used as the left operand of an assignment operator.