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Strings v chars
Character Strings example from a Well House Consultants training course
More on Character Strings [link]

This example is described in the following article(s):
   • Chars, char arrays and strings in C. Some early cautions and pitfalls. - [link]

Source code: chout.c Module: C206
/* Strings and chars in C

A String is a char array with a null (\0) on the end - so you refer to strings by the ADDRESS of
the first element but to chars by their value. And if you use a string function on the address
of a char variable, you'll also be accessing the following memory contents up to and including the
next byte which happens to be null. */


#include <stdio.h>
#include <string.h>

void centred(char *);

int main() {

        char capital = 'A';
        char *company = "Well House Consultants";

        printf ("The letter is %c.\n",capital);
        printf ("The company is %s.\n",company); /* From given address to null */
        printf ("The string is %s.\n",&capital); /* From given address to null */

        printf ("The string is %s.\n",&company[12]); /* From given address to null */

        centred(company);

}

void centred(char * headline) {
        char lyne[81]; /* Allow for 80 + terminating null */

        int insize, newstart;
        int k;

        for (k=0;k<80;k++) lyne[k] = '-';
        lyne[80] = '\0';

        insize = strlen(headline);
        newstart = (80 - insize ) /2;

        strcpy(&lyne[newstart],headline); /* String copy */
                                /* Sorry - if you copy a string with =, you copy the address
                                and you do NOT replicate the string as you might hope!
                                You have to use a function such as strcpy or strncpy (usually better)
                                instead*/


        lyne[newstart+insize] = '@'; /* strcpy has added a null and trucated lyne
                                Replace thet null with what it overwrote */

                                /* (or rather @ for demo purposes only) */

        printf("%s\n",lyne);

        /* lots more such as strncpy and strcmp (beware the return value of that) */

}

/*

munchkin:c12 grahamellis$ ./chout
The letter is A.
The company is Well House Consultants.
The string is A??_?.
The string is onsultants.
-----------------------------Well House Consultants@----------------------------
munchkin:c12 grahamellis$

*/

Learn about this subject
This module and example are covered on the following public courses:
 * Learning to Program in C
 * Learning to program in C and C++
 * Programming in C
 * C and C++ Programming
 * Learning to program in C and C++
 * C and C++ Programming
Also available on on site courses for larger groups

Books covering this topic
Yes. We have over 700 books in our library. Books covering C and C++ are listed here and when you've selected a relevant book we'll link you on to Amazon to order.

Other Examples
This example comes from our "Character Strings" training module. You'll find a description of the topic and some other closely related examples on the "Character Strings" module index page.

Full description of the source code
You can learn more about this example on the training courses listed on this page, on which you'll be given a full set of training notes.

Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.

Other resources
• Our Solutions centre provides a number of longer technical articles.
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The Horse's mouth provides a daily tip or thought.
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This web site is written and maintained by Well House Consultants.

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This is a sample program, class demonstration or answer from a training course. It's main purpose is to provide an after-course service to customers who have attended our public private or on site courses, but the examples are made generally available under conditions described below.

Conditions of use
Past attendees on our training courses are welcome to use individual examples in the course of their programming, but must check the examples they use to ensure that they are suitable for their job. Remember that some of our examples show you how not to do things - check in your notes. Well House Consultants take no responsibility for the suitability of these example programs to customer's needs.

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