Conversion.Val Method (Char)

 
System_CAPS_noteNote

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Returns the numbers contained in a string as a numeric value of appropriate type.

Namespace:   Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

public static int Val(
	char Expression
)

Parameters

Expression
Type: System.Char

Required. Any valid String expression, Object variable, or Char value. If Expression is of type Object, its value must be convertible to String or an ArgumentException error occurs.

Return Value

Type: System.Int32

Returns the numbers contained in a string as a numeric value of appropriate type.

Exception Condition
OverflowException

InputStr is too large.

ArgumentException

Expression is an Object type expression that is not convertible to String.

The Val function stops reading the string at the first character it cannot recognize as part of a number. Symbols and characters that are often considered parts of numeric values, such as dollar signs and commas, are not recognized. However, the function recognizes the radix prefixes &O (for octal) and &H (for hexadecimal). Blanks, tabs, and linefeed characters are stripped from the argument.

The following call returns the value 1615198.


Val(" 1615 198th Street N.E.") 

The following call returns the decimal value -1.


Val("&HFFFF") 
System_CAPS_noteNote

The Val function recognizes only the period (.) as a valid decimal separator. When different decimal separators are used, as in international applications, use CDbl or CInt instead to convert a string to a number. To convert the string representation of a number in a particular culture to a numeric value, use the numeric type's Parse(String, IFormatProvider) method. For example, use Double.Parse when converting a string to a Double.

System_CAPS_noteNote

An InvalidCastException exception might be raised in response to certain uncommon number formats. For example, the following code raises this exception.

' These examples cause run-time errors.

'Console.WriteLine(Val("1.34%"))

'Console.WriteLine(Val("1.34&"))

The conflict between the number formatted as a Double and the Integer and Long type characters would be caught by the compiler if it were not contained in a string.

' These examples cause compiler errors.

'Dim m = 1.34%

'Dim n = 1.34&

The following example uses the Val function to return the numbers contained in each string. Val stops converting at the first character that cannot be interpreted as a numeric digit, numeric modifier, numeric punctuation, or white space.

Dim valResult As Double
' The following line of code sets valResult to 2457.
valResult = Val("2457")
' The following line of code sets valResult to 2457.
valResult = Val(" 2 45 7")
' The following line of code sets valResult to 24.
valResult = Val("24 and 57")

.NET Framework
Available since 1.1
Silverlight
Available since 2.0
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