Member Avatar for Dee_Dee

I have to write a program that will check each value in the array for a negative number then the program must either print "The array has no negative values" or "The array has at least one negative value". We have to use the funcion anynegatives(int a[], int arraysize) This is my code so far.
Any help would be appreciated.

#include <iostream>
using std::cout;
using std::cin;
using std::endl;
#include <iomanip>

anyNegative(int a[], int arraysize);

int main()

{
	cont int arraysize=5;
	int a[arraysize];
	int i;
	cout<<"Enter "<<arraysize<<" integers: ";
	for (i=0; i=arraysize; i++)
		cin>>a[i];
{
	if( i >=0)
		cout<<"The array has no negative value";
	else
		cout<<"The array has at least one negative value";
}
	
	return 0;
}
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Dani AI

Generated

Good corrections from and — the task is simply to detect whether any element is negative and report that fact, but a few practical points make the solution robust and modern.

The original snippet from contains a few concrete mistakes (typo cont instead of const, a prototype without a return type, i = arraysize instead of a comparison, and incorrectly placed braces) and relies on a compiler extension (variable-length arrays). Prefer a clear, correct function signature and keep I/O separate from the checking routine so it can be tested independently. Also use the right integer type for sizes (std::size_t) and make parameters const where appropriate.

A compact, modern approach uses the standard container and algorithm library rather than raw VLAs:

#include <iostream>
#include <vector>
#include <algorithm>

bool contains_negative(const std::vector<int>& v) {
    return std::any_of(v.begin(), v.end(), [](int x){ return x < 0; });
}

// read N values into a vector, validate input, then call contains_negative(...)

Notes and troubleshooting checklist:

  • Keep the predicate function free of I/O and side effects; return bool to indicate presence.
  • Guard input: check std::cin for failures and ensure the container has the expected size before scanning.
  • For very old compilers or school assignments requiring plain arrays, use a const int size or pass the size explicitly; do not rely on VLAs.
  • Style: prefer std:: qualification (as suggested) in headers to avoid namespace pollution in larger projects.
  • Early return on the first negative is both correct and efficient for large datasets; for readability, prefer standard algorithms like std::any_of where available.

These points complement the working loop shown by and the corrected program layout from while addressing portability, correctness, and good habits for further assignments.

Recommended Answers

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Member Avatar for server_crash

You could simply loop through I guess:

bool anyNegatives(int nums[], int size)
{
   for (int i=0; i<size; ++i)
   {
      if (nums[i] < 0)
      {
          return true;
      }
   }
   return false;
}

Pretty simple. If you encounter one, then you can break.

Member Avatar for Cudmore

Hmmm, looks like dee_dee is quite new at this.. are you learning it in school?? Lets fix a few things here... mostly it's correct..

#include <iostream>
using namespace std; // (replaces the prior 3 lines)
// #include <iomanip> // what is this junk? lol

bool anyNegative(int a[], int arraysize);

int main()

{
	const int arraysize=5;
	int a[arraysize];
	int i;
	cout << "Enter " << arraysize << " integers: ";
	for (i=0; i<arraysize; i++)
		cin >> a[i]; // get values
{
	if(anyNegative(a, 5)==false)
		cout << "The array has no negative value\n"; // '\n' is same as endl
	else
		cout << "The array has at least one negative value" << endl;
}
	
	return 0;
}

// using server_crash's method:

bool anyNegative(int a[], int arraysize)
{
   for (int i=0; i<arraysize; i++)
   {
      if (a[i] < 0)
      {
          return true;
      }
   }
   return false;
}

Oh boy! :cheesy: I'm a n00b too.. but catching on, much like dee_dee

Member Avatar for Dee_Dee

Thanks for the help. Yeah i'm a noob. first course in school for C++

Member Avatar for Lerner

Many people would argue that limiting using directives to include only those items in a namespace that will be actually used instead of opening up all of the namespace would be prefered to something like the using namespace std statement. Even more limiting, and therefore more precise, if more onerous in the process of writing the code, is using the namespace name with the scope operator before each instance of something from the namespace, like this:

std::cout << "hello world" << std::endl;

Member Avatar for SpS

i agree to lerner

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