problem with itoa and string

[mark7930SRL]

Hi, i'm a student and I'm learnig C .I have this code

char string[5];
int16 value;

suppose that value is 14578.

itoa((int32)value,10, string);

String now becomes "14578".

How can I change one digit of string. ie: I want to change into 145C8 without subtraction. Can I Do it?

I use this code but is not good:

string[3]="C";

compiler say " Bad expression syntax "

thank's at all...

[Ttelmah]

Start by making your buffer bigger....
Remember that a 'string', has a terminating '\0', and there needs to be space for this as well. As it stands, you will be overwriting the next character in memory, with potentially disastrous result...
The problem with your replacement, is that "C" (with double inverted commas), is itself a _string_, not a single character. You can transfer a string like this. You need to use the single inverted commas, to say the 'character' C. So:

string[3]='C';

Best Wishes

[Ttelmah]

Replace "can", with "can't" on the penultimate line.....

Best Wishes

[RayJones]

Yep, as ttelmah said, you must cater for the hidden trailing '\0' so you need 6 bytes to hold the UNSIGNED integer, 7 if you venture into signed territory.

As an additional item, you can initialise a a string using:

char string[] = "a string";

ie don't worry about defining a size, the complier sorts that out, and includes the trailing zero for you.