Check whether figure has decimal point or not

Question

I need to check whether figure has decimal point or not.

Example.

Figure      Result
=====================
1           false
1.0         true
0.0         true
0           false

I found different solutions for check figure value is integer or double. But i want to check figure has decimal point or not. eg. Figure is 1.0 .it should return true result.

Can you please provide me better solutions?

This post answers what you want - http://stackoverflow.com/questions/2751593/how-to-determine-if-a-decimal-double-is-an-integer — shekhar, Oct 14 '15 at 05:46
Possible duplicate of [Check if a number has a decimal place/is a whole number](http://stackoverflow.com/questions/2304052/check-if-a-number-has-a-decimal-place-is-a-whole-number) — japzdivino, Oct 14 '15 at 06:30

nozzleman · Accepted Answer · 2015-10-14T06:12:17.453

Given the little input and assuming that what you call figure is given to you as a string, this is what comes to my mind.

var figures = new[] {"1", "1.0", "0.0", "0"};

foreach(var figure in figures) 
{
    if (figure.Contains("."))
    {
        Console.WriteLine("point");
    }
    else
    {
        Console.WriteLine("no point");
    }
}

Regex would probably be a better way to go.

foreach (var figure in figures)
{
    if (Regex.IsMatch(figure, @"^\d+\.\d+$"))
    {
        Console.WriteLine("{0}: Floatingpoint Number", figure);
    }
    else if (Regex.IsMatch(figure, @"^\d+$"))
    {
        Console.WriteLine("{0}: Integer Number", figure);
    }
    else
    {
        Console.WriteLine("{0}: No Number", figure);
    }
}

Yet again, you could use the TryParse-Methods of the types you want to check like that:

foreach (var figure in figures)
{
    int intOut;
    decimal decimalOut;

    // Note that you would have to check for integers first, because 
    // integers would otherwise be detected as valid decimals in advance.

    if (int.TryParse(figure, out intOut))
    {
        Console.WriteLine("{0}: Integer Number", figure);
    }
    else if (decimal.TryParse(figure, out decimalOut))
    {
        Console.WriteLine("{0}: Floatingpoint Number", figure);
    }
    else
    {
        Console.WriteLine("{0}: No Number", figure);
    }
}

If your figures are of type decimal, double or float, the easiest way to determine whether they would make valid integers it to do a modulo check like that:

decimal figure = 1.0m;
Console.WriteLine(figure % 1 == 0 ? "Integer Number" : "Floatingpoint Number"); // deviding by 1 leaves no remainder

You should be more specific on what your goal is, especially what type your figures are of.

Check whether figure has decimal point or not

1 Answers1