IsNumber with a String ArrayList

Question

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I want to know how to identify a whole string if it is a Number, instead of each digit (using the index).

Example:

string number = "-1.234";

char.IsNumber( number, 0 ); //Output = FALSE

Because the - is not a number, but if I check it as a whole number then it will be TRUE...

Any other way to do not use the index?

Posted 8-Oct-10 5:05am

jalmonte

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5 solutions

Solution 3

You can use a regular expression

Posted 8-Oct-10 5:13am

Sebastien T.

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Marc A. Brown · Accepted Answer · 2010-10-08T05:09:00

Solution 1

Could you use Decimal.TryParse?

Posted 8-Oct-10 5:09am

Marc A. Brown

Comments

jalmonte 8-Oct-10 11:14am

Like, double.TryParse(number, but what I put here if just want to see if is True or False )

Marc A. Brown 8-Oct-10 11:17am

You mean for the second (out) parameter? Create a variable of type double and pass it. If you don't need to know what the value is, just ignore the value of that variable after the call to TryParse. Make sense?

shakil0304003 · Accepted Answer · 2010-10-08T06:30:00

Solution 4

I think, you want like this

string number = "-1.234";
            double test = 0;

            if (double.TryParse(number,out test) && test >= 0)
                MessageBox.Show("Yes");
            else
                MessageBox.Show("No");

Posted 8-Oct-10 6:30am

shakil0304003

Comments

Dalek Dave 8-Oct-10 16:15pm

Good Answer

shakil0304003 9-Oct-10 2:59am

Thanks

Sauro Viti · Accepted Answer · 2010-10-08T05:13:00

Solution 2

Look at the Int32.TryParse Method[^] and Double.TryParse Method[^]: they returns true if the string content represents an int or a double respectively, and false otherwise.

Posted 8-Oct-10 5:13am

Sauro Viti

#realJSOP · Accepted Answer · 2010-10-08T08:06:00

Solution 5

You can also write an extension method that uses TryParse.

Posted 8-Oct-10 8:06am

#realJSOP