Cout/Cin with Arrays

[AndrewM]

In my programming class, we just learned about arrays yesterday. We had to create a test program that would receive 3 int values. My code is:

/* Andrew M
April 23, 2010
arrayProblem.cpp
Problems 2 and 7, pages 424 and 426
*/

//preprocessor directives
//allows usage of cin and cout
#include <iostream>

using namespace std;

int main ()
{ //begin main
system ("cls"); //clears the screen

//variable declarations
int threeValues [2];
int x;

for (x = 0; x < 3; x++)
{
cout << "Enter 3 integer values. " << endl;
cin >> threeValues [2];
}

cout << threeValues [0] << endl;
return 0;
} //end main

I get the following error message after I input the first value:

"Run-Time Check Failure #2 - Stack around the variable 'threeValues' was corrupted."

Could someone please tell me how to fix this?

[jRaskell]

Problem 1. Arrays in C++ use 0 based indexes. Your 3 variable array will have indexes 0, 1, and 2. Index 3 is out of bounds, and will cause a compile error.

Problem 2. cin >> threeValues [3]; Does not input 3 values. It only inputs a single value into index 3 (which we've already determined is out of bounds anyways). You will need a separate prompt for each index of the array, preferably done with a for() loop.

[AndrewM]

I editted my first post with the for() loop. The loop works, but when the I cout threeValues [0], it displays -858993460 and still shows the same error message...

[oghmaosiris]

try:
cout << "Enter 3 integer values. " << endl;

for (x = 0; x < 3; x++)
{
cin >> threeValues [x];
}

[AndrewM]

The for () loop you posted worked, and when I cout threeValues [0], it shows t he correct number. The only problem is that I still get the same error message....

[Soaps]

When you initialize the array,

//variable declarations
int threeValues [2];

you are only giving it 2 elements, threeValues[0] and threeValues[1]. Thus when you run the for() loop and take in three integers, you get the error because you did not make a spot for the third.

Also, when you go to output the three numbers, use the same logic as the for() loop posted above, to cycle through and cout each element.