by Dinesh Thakur Category: Puppetting On Strings

The standard C library provides several functions for converting numbers of all formats (integers, longs, floats, and so on) to strings and vice versa The following functions can be used to convert integers to strings :

 
by Dinesh Thakur Category: Puppetting On Strings

We may want to know the number of words in a given string and the average word length. The English text contains words (i. e., sequences of letters) separated by spaces, newlines and punctuation marks such as period, comma, semicolon, colon, quotation marks, exclamation, question mark, etc. It is quite a difficult job to separate the words from these punctuation marks. However, this task is greatly simplified when we use the powerful strtok function provided in the standard C library. The program given below determines the number of words in a given string and the average word length.

 
by Dinesh Thakur Category: Puppetting On Strings

The function dstr_read given below reads a string from the keyboard into array buf, stores it in dynamically allocated memory and returns a pointer to it.

 
by Dinesh Thakur Category: Puppetting On Strings

The function accepts two strings, str1 and str2, as parameters of type char * and exchanges their contents. Note that the strcpy function is used to copy the strings and a local character array is used to store string strl temporarily. This function can be called from the main function to exchange strings as shown below.

 
by Dinesh Thakur Category: Puppetting On Strings

Single characters can be replaced in a string. Given the following declarations, several things are possible.

 
by Dinesh Thakur Category: Puppetting On Strings

String Processing (Storing Strings and String Operations) : In C, a string is stored as a null-terminated char array. This means that after the last truly usable char there is a null, hex 00, which is represented in C by '\0'. The subscripts used for the array start with zero (0). The following line declares a char array called str.

 
by Dinesh Thakur Category: Puppetting On Strings

The standard C library provides several functions for converting strings to numbers of all formats (integers, longs, floats, and so on) and vice versa.

 
by Dinesh Thakur Category: Puppetting On Strings

In C language, a string is defined as a variable length array of characters terminated by the null character ('\O'). Letters such as A, b, C, etc., digits such as 1, 2, 3, etc., and special symbols such as +,- ,*, [] , () , etc., except a few control characters, may be included in a string. The various functions of C Standard Library for manipulation of strings are contained in header file <string.h>.

 
by Dinesh Thakur Category: Puppetting On Strings

A typical call to the strcmp function take the following form:

strcmp( s1, s2)

 
by Dinesh Thakur Category: Puppetting On Strings

A string is defined to be an array of characters. If it is desired to have an array of strings such as a list of names, it becomes similar to an array whose elements are also arrays. Therefore, an array of strings is a two-dimensional array; it may be declared as below.

 
by Dinesh Thakur Category: Preprocessor Directives

A macro may be used in the definition of another macro as illustrated below.

 
by Dinesh Thakur Category: Preprocessor Directives

Macros may also be created by #define. Here the identifier can have parameters but types of parameters are not mentioned.

#define identifier(parameters) replacement_text

 
by Dinesh Thakur Category: Preprocessor Directives

The directive #define is used to create symbolic constants and macros (small function type entities). The directive #define may be used in the following manner:

 
by Dinesh Thakur Category: Preprocessor Directives

The conditional directives are meant to control the compilation process. By using them we may conditionally include certain statements of the program for compilation. If the condition is not met the statements are not included. These directives also help us not to include duplicate files in the program and cause error. For example, see the following code:

 
by Dinesh Thakur Category: Preprocessor Directives

The token # single in its own line is null directive. It is simply neglected by compiler. Thus, if the code is simply as given below, it is neglected by the compiler.

 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.