Thread: problem with Array

Hi

I have declared a char array inside a local method

char tempID[16] ;

Then I read some characters from the serial port, storing everything in the array "txt". char txt[40];

I want to copy 16 characters (from the 5th to the 20th) from "txt to the tempID array, I have done it with a for loop:

for(int i=0; i<sizeof(tempID); i++)
{
tempID[i] = txt[i+4];

}

The PROBLEM is that when I display the tempID array I get all the right characters PLUSS a final character that I have no idea where comes from. (It´s a non-printable character, probalby CR or LF). Thought it was a problem with the for loop and appended some extra characters on the txt-string but the problem remains.

Any suggestions would be appreciated.


doneirik

Originally Posted by FillYourBrain

c strings require a null terminator. Your loop does not provide this. You need to set the (i+1)st byte to 0 or '\0'

I know....but though the "txt" array has been converted (automatically) to a string through the use of strcat, I need the tempID array as an clean array and not as a string. (cause I need to send it through the serial port again and it must comply with the protocol of the external hardware)


doneirik

Ok.
I display it using this->textBox1->Text = tempID;

But...A few lines later in my code I copy again the 16 characters in the tempID array into a new array

char TagID[16];
for(int i = 0; i<sizeof(tempID); i++)
{
TagID[i] = tempID[i];
}

displaying this array using the same methods works ok. The extra character is only appended in the first case.
...it is sort of annoying...