Thread: non initialized warnings??

I'm not sure if I should post this on the DevC++ forum on sourceforege but whatever, maybe it'll help someone.

I recently had the following code to compute an the average in an array's rows

PHP Code:

double RowAvg(const double arr[][CLM], int row){
    /* computes average of each set of numbers. using 1 demensional array method */
    int i;
    double avg;
    for(i = 0; i<CLM; i++)
        avg+= arr[row][i]; /* this gives the given row and adds all elements in that row */
     
    avg = avg / CLM;   
    return avg; 
} 


for the life of me I couldn't figure out why the ouput would be ouptut like this

PHP Code:

Enter row 0 element 0 : 122
Enter row 0 element 1 : 233.3
Enter row 0 element 2 : 33.5
Enter row 1 element 0 : 233
Enter row 1 element 1 : 93
Enter row 1 element 2 : 233
This array contains:

Row 0:  122.000 233.300 33.500
Row 1:  233.000 93.000 233.000
The avg of row 1 is 264764614254408340000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000
0000000000000000000000000000000000000000000000000.000
The avg of row 2 is 882548714181361150000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000.000
The avg of row 3 is 294182904727120370000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000000000000000000000000000000000000000000000000000
000000000000000000000000000000000000000000000000.000
The avg of the total array is 315.933 


when i finally tracked the problem down, it was so simple I wanted to smack my self. Most of you know but I had for gotten to initialize avg to 0. THAT'S IT.

I Understand C's philosophy is not to get in the way of the programmer, but wow. in another language if i had done lets say[

PHP Code:

#language unknown :D 
>>> l = [1,2,3,4,5,6,7]
>>> for num in l:
    avg+=num
    avg2 = avg / len(l) 


I'd get this output

PHP Code:

Traceback (most recent call last):
  File "<pyshell#4>", line 2, in -toplevel-
    avg+=num
NameError: name 'avg' is not defined 


really simple??? I guess my beef is: is it too much to ask for C to help me out once in awhile. i mean I know it has it's idiosyncasies but sheesh!!!..

that's my two cents, my ten cents is free.

Originally Posted by sand_man

In C you have the power to do what you want
C thought you didnt want avg initialised.

what compiler are you using? maybe up the warning levels

I'm using dev C++ 4.9.8.10

I can accept the responsibilty. I just figue a little help would be good now and then

niceeeee....thanks man.

you'd think they would just have these warnings installed but i suppose they just go along with the C and unix philosopy. Don't get in the programmers way.

Still, its nice to know. Thanks again guys.
Maybe that'll be one of my projects when i'm good enough. ARealDecent Compiler. or call it BabyC or something.

Originally Posted by caroundw5h

you'd think they would just have these warnings installed but i suppose they just go along with the C and unix philosopy. Don't get in the programmers way.

Maybe that'll be one of my projects when i'm good enough. ARealDecent Compiler. or call it BabyC or something.

Dev-C++ is good. You just need to learn how to configure it.

project / options / compiler / Command line ...

I suggest

-W -Wall -O2

as a minimum.