once defined ,string cannot be initialized to other characters?

Question

Using pointers string can be initialized to other characters but when once string has been defined it cannot be initialized to other characters.What is the reason behind it??

int main()
{
char str1[]="hello";
char *p="hello";
str1="bye";/*error*/
p="bye";/*works*/
}

Nick: In this case, the * (in "char *p") means that p is a pointer variable. That is, the variable p doesn't contain a character, but the address to a place in memory where there is a character. — Thomas Padron-McCarthy, Jul 08 '12 at 08:33
pl. also see some useful links http://c-faq.com/decl/strlitinit.html — Tanmoy Bandyopadhyay, Jul 08 '12 at 08:37
A more pertinent duplicate would discuss the use of `strcpy()` et al for assigning to strings. The proposed duplicate does not do that. Other questions might be more appropriate. A casual search found: [Why is `strcpy()` necessary?](http://stackoverflow.com/questions/6901090/) and [Why does a char array need `strcpy` and `char *` doesn't](http://stackoverflow.com/questions/11508233/). — Jonathan Leffler, Apr 01 '14 at 05:22

score 1 · Answer 1 · answered Jul 08 '12 at 08:19

1

You've defined str1 as an array, and arrays aren't assignable.

You can, however, copy other data into the array, for example:

char str1[] = "hello";

strcpy(str1, "bye");

answered Jul 08 '12 at 08:19

Jerry Coffin

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score 0 · Answer 2 · answered Jul 08 '12 at 08:19

0

To change the characters in an array such as what you are doing you have to use a function such as strcpy or do it index by index.

str1[0] = 'p';

will print out pello

What you are trying to do is not supported by the C language.

answered Jul 08 '12 at 08:19

sean

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score 0 · Accepted Answer · answered Jul 08 '12 at 08:23

Arrays are arrays and pointers are pointers. Defining arrays gives the pointer to the allocated array, that is a constant pointer to the location where the array space hass been reserved. That is a concrete address in the lifo stack. So, str1 is a constant pointer value and you cannot change it. You cannot set the value of the address of a different constant string.

Defining pointers, as char*p, gives you a variable value of an address. And so, you can change de value of the variable p.

once defined ,string cannot be initialized to other characters?

3 Answers3