CODEWITHSUNDEEP
c#
user7739271
user7739271

Reputation:

'maxValue' must be greater than zero

I'm not sure it's an issue, but something looks like not correct in the message.

My first try:

try
{
    var r = new Random();
    Console.WriteLine(r.Next(-1));
}
catch (Exception e)
{
    Console.WriteLine(e.GetType().ToString());
    Console.WriteLine(e.Message);
}

Output:

System.ArgumentOutOfRangeException

'maxValue' must be greater than zero.

Parameter name: maxValue

My second try:

try
{
    var r = new Random();
    Console.WriteLine(r.Next(0));
}
catch (Exception e)
{
    Console.WriteLine(e.GetType().ToString());
    Console.WriteLine(e.Message);
}

Output:

0

So, the problem is: why is 0 greater than zero?

Upvotes: 2

Views: 3829

Answers (5)

Reshma
Reshma

Reputation: 446

The value cant be negative.zero or above is acceptable.That's why your are getting above answer.

Upvotes: 0

jegtugado
jegtugado

Reputation: 5141

By definition from MSDN Random.Next Method (Int32).

maxValue Type: System.Int32 The exclusive upper bound of the random number to be generated. maxValue must be greater than or equal to 0.

So yes we can say that the error message is misleading. It should be greater than or equal to zero.

Upvotes: 1

kgzdev
kgzdev

Reputation: 2885

Parameters

maxValue

Type: System.Int32 The exclusive upper bound of the random number to be generated. maxValue must be greater than or equal to 0.

From Random.Next Method (Int32)

Upvotes: 0

Nkosi
Nkosi

Reputation: 247058

Random.Next Method (Int32)

maxValue: The exclusive upper bound of the random number to be generated. maxValue must be greater than or equal to 0.

Upvotes: 0

Oliver
Oliver

Reputation: 45101

If you take a look at the source code:

  /*=====================================Next=====================================
  **Returns: An int [0..maxValue)
  **Arguments: maxValue -- One more than the greatest legal return value.
  **Exceptions: None.
  ==============================================================================*/
  public virtual int Next(int maxValue) {
      if (maxValue<0) {
          throw new ArgumentOutOfRangeException("maxValue", Environment.GetResourceString("ArgumentOutOfRange_MustBePositive", "maxValue"));
      }
      Contract.EndContractBlock();
      return (int)(Sample()*maxValue);
  }

The value must be positive and zero is positive.

Upvotes: 1

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