Getting -858993460 as a result c++

Question

The program send me -858993460 value on a[ch] an b[nech] why ?? i cant understand that ... if i use cout<<m[i] on place of cout<<a[ch]<<endl; it works fine ... shows me the even and odds but when i try to send them to another array the value goes wrong ( I need those another two arrays a[ch] and b[nech])

#include <iostream>
#include <conio.h>
#include <string>
#include <cstdlib>
#include <stdlib.h>
using namespace std;
int main()

 {
int i,n;
int m[3], a[3]={0}, b[3]={0};
int ch=0, nech=0;
for(i=0; i<3; ++i)
{
    cout<<i+1<<". Studenski fark. nomer: ";
    do
    {
        cin>>m[i];
    }
    while(!(m[i]>=1e7 && m[i]<1e8));
    if(m[i]%2==0)
    {
        m[i]==a[ch]; ch++;
        //cout<<m[i]<<endl; "without the down 'fors' it works"
    }
    else 
    {
        m[i]==b[nech]; nech++;
        //cout<<m[i]<<endl; "without the down 'fors' it works"
    }
}
cout<<"\nVsichki fakultetni nomera: "<<endl;
for(i=0; i<3; ++i)
cout<<m[i]<<"\t";
cout<<"Chetni fark nomera: \n";
if(ch!=0)
    for(i=0;i<ch;i++)
        cout<<a[ch]<<"\t"; //"with {0} on 'a' I receive 0 as result"
else 
    cout<<"nqma chetni fak nomera";
if(nech!=0)
    for(i=0;i<nech;i++)
        cout<<b[nech]<<"\t"; //"same here 0 as result with {b}"
else
    cout<<"Nqma nechetni fak nomera";

getch();
 }

It would help if you described what you're trying to achieve. What's `a[]` and `b[]` supposed to do? — Angew is no longer proud of SO, Nov 12 '12 at 11:12
The value is not a random one, is 0xcccccccc in hex, which in Visual Studio is an uninitialized int in debug mode. — Zac, Sep 10 '15 at 13:49
-858993460 = 0xCCCCCCCC which means [you've accessed uninitialized memory](https://stackoverflow.com/q/370195/995714) — phuclv, Aug 18 '18 at 11:06

score 3 · Answer 1 · answered Nov 12 '12 at 11:05

3

You need to initialize your arrays

int m[3] = {0}
int a[3] = {0};
int b[3] = {0};

Without initializing the array, the value is random value from stack.

answered Nov 12 '12 at 11:05

billz

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no it doesnt work.. now it shows me only 0 0 0 as a result .. – Nikola Obretenov Nov 12 '12 at 11:09
first you got value to `cin>>m[i];` but m[i] reset again by `m[i]=a[ch]; ch++;` – billz Nov 12 '12 at 11:12
ok check the edited code ... it works fine in first for but when i try to use them down in the next for it gets the same ... – Nikola Obretenov Nov 12 '12 at 11:33
can you type me the full program with my code... i'm getting those 0 0 0 as result ... can't do my next check – Nikola Obretenov Nov 12 '12 at 11:43

score 1 · Answer 2 · answered Nov 12 '12 at 11:03

1

m[i]=a[ch] is undefined behavior because a is an array of uninitialized ints.

You're never reading into a. What would you expect the behavior to be?

answered Nov 12 '12 at 11:03

Luchian Grigore

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in addition, with `m[i]=a[ch]; ch++; cout< beyond array size... – codeling Nov 12 '12 at 11:05
how to unitialisite it ... when i try to set in the a[ch] b[nech] with ={0} result is 0 ... – Nikola Obretenov Nov 12 '12 at 11:13

score 0 · Answer 3 · answered Nov 12 '12 at 11:05

0

You're not initialising the elements of a and b anywhere, so they have pretty much random initial value (e.g. the -858993460 you're getting).

answered Nov 12 '12 at 11:05

Angew is no longer proud of SO

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Getting -858993460 as a result c++

3 Answers3