CODEWITHSUNDEEP
c++booleannegative-number
Sean
Sean

Reputation: 867

How to figure out if the first index in an array is a negative sign

I am trying to write a bool function that looks at the first index in an array which contains a positive or negative number and classifies if it is a negative sign (i.e. -). If it is a negative Sign it returns false everything else returns true. I am trying to figure out how to compare the negative sign. The following code give an error because of the '-'

    bool BigNum::get_positive() const
{
char '-';
if(digits[0] == '-')
{
    return false;
}
else
{
    return true;
}
}

Upvotes: 0

Views: 176

Answers (3)

Vineet G
Vineet G

Reputation: 195

Mistake lies in line char '-'. '-' is supposed to be stored in some variable which later could be used in if clause to compare. This is a syntactical error because you havn't defined a storage for '-'.

Otherwise as pointed above just delete this line and get away with using '-' in if (as you have already done it)

Upvotes: 1

Miguel Angel
Miguel Angel

Reputation: 640

you must delete or comment "char '-';"

Upvotes: 1

Anson
Anson

Reputation: 2674

char '-';

The compiler thinks you're trying to declare a char, but that's not a valid declaration.

Your entire function could be replaced with:

return (digits[0] != '-');

Of course, this is assuming that [0] is a valid index of digits. If not, bad things will happen. If you know the length of the array, you can do a check like this:

if( digits_length < 1 )
  return false;
return (digits[0] != '-');

Upvotes: 5

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