[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'DB' (#fcl)

# TField.ValidChars

Characters that are valid input for the field's content

## Declaration

Source position: db.pas line 436

`public property TField.ValidChars : TFieldChars read FValidChars write FValidChars;`

## Description

ValidChars is a property that is initialized by descendent classes to contain the set of characters that can be entered in an edit control which is used to edit the field. Numerical fields will set this to a set of numerical characters, string fields will set this to all possible characters. It is possible to restrict the possible input by setting this property to a subset of all possible characters (for example, set it to all uppercase letters to allow the user to enter only uppercase characters. TField itself does not enforce the validity of the data when the content of the field is set, an edit control should check the validity of the user input by means of the IsValidChar function.

## See also

TField.IsValidChar |  | Check whether a character is valid input for the field