check whether array contains false?

Question

How to check the array true_or_false containing a value of false?

bool[] true_or_false = new bool[10];

for (int i = 0; i < txtbox_and_message.Length; i++)
{
  bool bStatus = true;
  if (txtbox_and_message[i] == "")
  {
    bStatus = false;
  }
  true_or_false[i] = bStatus;                           
}

Answer 1

Intead of your code:

bool containsEmptyText = txtbox_and_message.Contains( t => t.Text ==String.Empty)

Answer 2

return true_or_false.Any(p => !p);

Answer 3

using System.Linq;

then:

true_or_false.Contains(false);

Answer 4

If they are not all true, then at least one is false.

Therefore:

!true_or_false.All(x => x)

Docu: http://msdn.microsoft.com/en-us/library/bb548541.aspx

EDIT: .NET 2.0 version, as requested:

!Array.TrueForAll(true_or_false, delegate (bool x) { return x; })

or

Array.Exists(true_or_false, delegate (bool x) { return !x; })

NOTE: I've been staying away from the nonsensical code that sets true_or_false, but it could be that what you want is:

int emptyBox = Array.FindIndex(txtbox_and_message, string.IsNullOrEmpty);

which will give you -1 if all the strings are non-empty, or the index of the failing string otherwise.

Answer 5

There are a couple of solutions:

Solution 1: do a for loop after that for loop to check if the true_or_false contains false like this:

if you want to achieve this without fancy tricks, and you want to program the code yourself you can do this:

bool containsFalse = false;
for(int j = 0; j < true_or_false.Length; j++)
{
   //if the current element the array is equals to false, then containsFalse is true,
   //then exit for loop
   if(true_or_false[j] == false){
       containsFalse = true;
       break;
   }
}

if(containsFalse) {
  //your true_or_false array contains a false then.
}

Solution 2:

!true_or_false.All(x => x);

PK

Answer 6

If on .NET3.5+ you can use System.Linq, and then check using Any:

// if it contains any false element it will return true
true_or_false.Any(x => !x); // !false == true

If you can't use Linq, then you have other choises:

Using Array.Exists static method: (as Ben mentioned)

Array.Exists(true_or_false, x => !x);

Using List.Exists (you would have to convert the array to a list to access this method)

true_or_falseList.Exists(x => !x);

Or you will need to iterate through the array.

foreach (bool b in true_or_false)
{
    if (!b) return true; // if b is false return true (it contains a 'false' element)
}
return false; // didn't find a 'false' element

---

Related

• Linq .Any VS .Exists

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And optimizing your code:

bool[] true_or_false = new bool[10];

for (int i = 0; i < txtbox_and_message.Length; i++)
{
    true_or_false[i] = !String.IsNullOrEmpty(txtbox_and_message[i]);
}