I find myself often needing to use Integer.TryParse to test if a value is an integer. However, when you use TryParse, you have to pass a reference variable to the function, so I find myself always needing to create a blank integer to pass in. Usually it looks something like:
Dim tempInt as Integer If Integer.TryParse(myInt, tempInt) Then
I find this to be quite cumbersome considering that all I want is a simple True / False response. Is there a better way to approach this? Why isn't there an overloaded function where I can just pass the value I want to test and get a true / false response?
Parse() method throws an exception if it cannot parse the value, whereas TryParse() method returns a bool indicating whether it succeeded. However, TryParse does not return the value, it returns a status code to indicate whether the parse succeeded and does not throw exception.
TryParse(String, Int32) Converts the string representation of a number to its 32-bit signed integer equivalent. A return value indicates whether the conversion succeeded.
TryParse method converts a string value to a corresponding 32-bit signed integer value data type. It returns a Boolean value True , if conversion successful and False , if conversion failed.
When this method returns, contains the 32-bit signed integer value equivalent to the number contained in s, if the conversion succeeded, or zero if the conversion failed. But what happens if the passed string itself is a string representation of '0'. So the TryParse will return zero.
No need to declare the integer.
If Integer.TryParse(intToCheck, 0) Then
or
If Integer.TryParse(intToCheck, Nothing) Then
If you have .Net 3.5 ability you can create an extension method for strings.
Public Module MyExtensions <System.Runtime.CompilerServices.Extension()> _ Public Function IsInteger(ByVal value As String) As Boolean If String.IsNullOrEmpty(value) Then Return False Else Return Integer.TryParse(value, Nothing) End If End Function End Module
And then call like:
If value.IsInteger() Then
Sorry, getting carried away I know, but also you can add this to the MyExtensions class above in .Net 3.5 and not worry unless you need validations.
<System.Runtime.CompilerServices.Extension()> _ Public Function ToInteger(ByVal value As String) As Integer If value.IsInteger() Then Return Integer.Parse(value) Else Return 0 End If End Function
Then simply use
value.ToInteger()
This will return 0 if it isn't a valid Integer.
Since you are using VB.net you can use the IsNumeric Function
If IsNumeric(myInt) Then 'Do Suff here End If
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