atoi function

[felixb]

hello,

I am new here and I have a question about this code:
"
int num;
char a[4];

a[0]=9;
a[1]=4;
a[2]=NULL;
a[3]=NULL;

num=atoi(grade);
"

I have a char array (a) that have (9 4 NULL NULL) i want to extract only the 94 using atoi function.
but, when I run the program the atoi function return 0. why?

thnk you,

[dcs]

You probably meant to have

a[0] = '9';
a[1] = '4';
a[2] = '\0';
a[3] = '\0';

This is more easily written (as an initialized array) as:

char a[4] = "94";

[felixb]

no... but the point is that i have array and each cell have digit...
i tried now with '\0' but it still return 0

[dcs]

Try looking more closely at my previous response: 9 is not the same as '9'. Use copy and paste if need be.

[dcs]

<<double post -- please delete>>

[felixb]

thank you very much for your help

[Chinmoy]

you have used atoi(grade).
What is grade? Its not declared anywhere! Use atoi(a).A is where you stored the data!
And '\0' and NULL dont make a difference. One is a escape sequence representation and the other is a high level text, resulting both in an eof.

[felixb]

it's ok.
the problem was that I done a[1]=9 instead of a[1]='9'

[dcs]

Originally Posted by Chinmoy

And '\0' and NULL dont make a difference. One is a escape sequence representation and the other is a high level text, resulting both in an eof.

'\0' and NULL may be different (a character vs a pointer), and neither has anything in common with EOF (a negative integer).

[Chinmoy]

'\0' and NULL have the same implication. Just that NULL works good with pointers and '\0' works good with char arrays.By eof here i wanted to mean end of input buffer..