Friday 10, February 2012
Welcome Guest, Register | Login  
      Home    |    Tutorials    |    Free Ebooks    |    Free Scripts    |    Articles    |    Blog     |    Forum    |    About Us    |    Contact Us

Strings in C++

Strings are arrays of chars. String literals are words surrounded by double quotation marks.
 
"This is a static string"
To declare a string of 49 letters, you would want to say:
 
char string[50];
This would declare a string with a length of 50 characters. Do not forget that arrays begin at zero, not 1 for the index number. In addition, a string ends with a null character, literally a '\0' character. However, just remember that there will be an extra character on the end on a string. It is like a period at the end of a sentence, it is not counted as a letter, but it still takes up a space. Technically, in a fifty char array you could only hold 49 letters and one null character at the end to terminate the string.

TAKE NOTE: char *arry; Can also be used as a string. If you have read the tutorial on pointers, you can do something such as:
 
arry = new char[256];
which allows you to access arry just as if it were an array. Keep in mind that to use delete you must put [] between delete and arry to tell it to free all 256 bytes of memory allocated.

Example:
delete [] arry.
Strings are useful for holding all types of long input. If you want the user to input his or her name, you must use a string. Using cin>> to input a string works, but it will terminate the string after it reads the first space. The best way to handle this situation is to use the function cin.getline. Technically cin is a class (a beast similar to a structure), and you are calling one of its member functions. The most important thing is to understand how to use the function however.

The prototype for that function is:
istream& getline(char *buffer, int length, char terminal_char);
The char *buffer is a pointer to the first element of the character array, so that it can actually be used to access the array. The int length is simply how long the string to be input can be at its maximum (how big the array is). The char terminal_char means that the string will terminate if the user inputs whatever that character is. Keep in mind that it will discard whatever the terminal character is.

It is possible to make a function call of cin.getline(arry, 50); without the terminal character. Note that '\n' is the way of actually telling the compiler you mean a new line, i.e. someone hitting the enter key.

Example:  
#include

using namespace std;

int main()
{
  char string[256];                              

  cout<<"Please enter a long string: ";
  cin.getline ( string, 256, '\n' );                cout<<"Your long string was: "<< string <
  cin.get();
}
Remember that you are actually passing the address of the array when you pass string because arrays do not require an address operator (&) to be used to pass their address. Other than that, you could make '\n' any character you want (make sure to enclose it with single quotes to inform the compiler of its character status) to have the getline terminate on that character.

cstring is a header file that contains many functions for manipulating strings. One of these is the string comparison function.
 
int strcmp ( const char *s1, const char *s2 );
strcmp will accept two strings. It will return an integer. This integer will either be:
 
Negative if s1 is less than s2.
Zero if s1 and s2 are equal.
Positive if s1 is greater than s2.
Strcmp is case sensitive. Strcmp also passes the address of the character array to the function to allow it to be accessed.
 
char *strcat ( char *dest, const char *src );
strcat is short for string concatenate, which means to add to the end, or append. It adds the second string to the first string. It returns a pointer to the concatenated string. Beware this function, it assumes that dest is large enough to hold the entire contents of src as well as its own contents.
 
char *strcpy ( char *dest, const char *src );
strcpy is short for string copy, which means it copies the entire contents of src into dest. The contents of dest after strcpy will be exactly the same as src such that strcmp ( dest, src ) will return 0.
 
size_t strlen ( const char *s );
strlen will return the length of a string, minus the termating character ('\0'). The size_t is nothing to worry about. Just treat it as an integer that cannot be negative, which it is.

 
     
   
C++ Tutorial
 
  Introduction to C++
Introduction to C++
  Variables in C++
Variables in C++
  if statement in C++
if statement in C++
  Looping in C++
Looping in C++
  break & continue statements
break & continue statements
  Switch Case Statement
Switch Case Statement
  C++ Functions
C++ Functions
  Pointers in C++
Pointers in C++
  Arrays in C++
Arrays in C++
  Strings in C++
Strings in C++
  Structures in C++
Structures in C++
  C++ File I/O
C++ File I/O
  Typecasting in C++
Typecasting in C++
  C++ Classes
C++ Classes
  Recursion in C++
Recursion in C++
  Inheritance in C++
Inheritance in C++
  Initilization Lists in C++
Initilization Lists in C++
  Enumerated Types in C++
Enumerated Types in C++
  Templates in C++
Templates in C++
  C++ Preprocessors
C++ Preprocessors
 
 
 
Web Designing Tutorials
  HTML Tutorial
HTML Tutorial
  DHTML Tutorial
DHTML  Tutorial
  CSS Tutorial
CSS Tutorial
  XHTML Tutorial
XHTML Tutorial
 
Programming Languages Tutorials
  C Language Tutorial
C Language Tutorial
  C++ Tutorial
C++ Tutorial
  Java Language Tutorial
Java Language Tutorial
  Data Structure Theory Tutorial
Data Structure Theory Tutorial
 
Server Side Scripting Tutorials
  PHP Tutorial
PHP Tutorial
  SQL Tutorial
SQL Tutorial
  ASP Tutorial
ASP Tutorial
 
Client Side Scripting Tutorials
  JavaScript Tutorial
JavaScript Tutorial
  VBScript Tutorial
VBScript Tutorial
 
 
 
POPULAR E-BOOKS
 
Download Pocket Mentor Formula  Ebook Pocket Mentor Formula
   
Download 	C Elements of Style Ebook C Elements of Style
   
Download Glossary of Search Engine Ranking Term Ebook Glossary of Search Engine Ranking Term
   
Download Capability-Based Computer Systems  Ebook Capability-Based Computer Systems
   
Download SEO Project Template Ebook SEO Project Template
   
 
Studiesinn.com © 2012 All Rights Reserved.
Website Designed & Developed by TechXprtz