B4J Question isNumber("1f") =>> TRUE !!

Tayfur · Dec 24, 2016

I looked a n interesting result with "isnumber" function.
"1f" and "1d" returned TRUE !!!!
why?

B4X:

If IsNumber("1f") Then Log("f")' return f
If IsNumber("ff") Then Log("a")'------
If IsNumber("1ff") Then Log("a")'------
If IsNumber("1f1") Then Log("a")'------
        If IsNumber("1e") Then Log("e")'------
        If IsNumber("1d ") Then Log("d") ' return d
        If IsNumber("1c") Then Log("c")'------
        If IsNumber("1b") Then Log("b")'------
        If IsNumber("1a") Then Log("a")'------

moster67 · Dec 24, 2016

Probably float and double literals. In Java you can use the suffix "d" or "f" to enforce double or float respectively...
http://stackoverflow.com/questions/4331200/what-do-f-and-d-mean-at-the-end-of-numeric-literals

Tayfur · Dec 24, 2016

moster67 said:
Probably float and double literals. In Java you can use the suffix "d" or "f" to enforce double or float respectively...
http://stackoverflow.com/questions/4331200/what-do-f-and-d-mean-at-the-end-of-numeric-literals

my code broke for this issue (
how can i fix it? it has a different verison or parameter (isNumber)?

I want to simple check for number.

moster67 · Dec 24, 2016

Try something like this:

B4X:

Dim x As String = "1d"
 
    If IsNumber(x) Then
        Log("is number")
        'double-check
        If x.EndsWith("D") Or x.EndsWith("d") Or x.EndsWith("F") Or x.EndsWith("f") Or x.EndsWith("L") Or x.EndsWith("l") Then
            Log("not a number")
        End If
    Else
       'no number
    End If

Also "L" or "l" can be used in Java to indicate long (normally capital letter "L" is used since the non capital letter "l" can be confused with the number one (1)

There may be better solutions...

Erel · Dec 25, 2016

B4X:

Sub TestNumber(s As String) As Boolean
   Return IsNumber(s) And Regex.IsMatch("[\d\.]+", s)
End Sub

B4J Question isNumber("1f") =>> TRUE !!

Tayfur

Well-Known Member

moster67

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Tayfur

Well-Known Member

moster67

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Erel

B4X founder

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B4J Question isNumber("1f") =>> TRUE !!

Tayfur

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moster67

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Erel

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