Thread: loop to get greatest and least number, its not working please help

What if amount is zero?

If you wanted to be picky about English, too, you're using lots of single 't's where there should be two.



[edit]

Good now? What are VLAs?

Variable Length Arrays.

Good now?

No, you still have a VLA. [/edit]

Riiight. Well, I guess we know which compiler you have.

Besides, that's the point. It wouldn't work if your compiler didn't have that extension.

And it will still break if you enter 0 for amount. Or "cat" or something. But it's just a demonstration, after all.

If the compiler supports them as an extension, they should work - in a limited way. If you have very large amounts of data, you may not be able to store it all in a VLA (it has rather limited memory capacity), whereas a vector would handle that amount of data just fine.

Just noticed you declared this:

Code:

int *num = new int[amount];

But you did not delete the allocated memory... thus you have a dangling pointer.

And I dont see the reason for allocating memory in such a simple program, you can accomplish
the task without using a pointer at all.

Just noticed you declared this:

Code:

int *num = new int[amount];

But you did not delete the allocated memory... thus you have a dangling pointer.

Fourth-last line.

Code:

delete [] num;

And I dont see the reason for allocating memory in such a simple program, you can accomplish
the task without using a pointer at all.

Unless you using a standard container, you need to allocate memory dynamically if you want any number of numbers to be supported. (And of course, the standard containers like std::vector just allocate memory behind the scenes.)

Assuming that you have to store the values at all, of course. I'd use something like this:

Code:

#include <iostream>
#include <climits>

int main() {
    int num, max = INT_MIN, min = INT_MAX;
    bool did = false;

    while(std::cin >> num) {
        if(num < min) min = num;
        if(num > max) max = num;
        did = true;
    }

    if(!did) std::cout << "No numbers entered.\n";
    else {
        std::cout << "Minimum: " << min << std::endl
            << "Maximum: " << max << std::endl;
    }

    return 0;
}

(Disclaimer: I have not tested it, only proved it correct. [Donald E. Knuth] Actually, I didn't even prove it correct. )

[edit] The exact quote is "I have only proved it correct, not tried it." [/edit]

Ah sorry dwks I missed that line and yes of course you are correct

Ah sorry dwks I missed that line

Yet another reason why RAII rocks

Cool, then both the least and the greatest will be -99 when the loop exits.

IF the loop exits - which won't happen if the user presses Ctrl+Z/Ctrl+D or enters a letter or the input comes from a file where the last number isn't -99 or which contains a letter.