---
url: /flow/guide/scripting-reference/functions/numeric/isdigit.md
---

# IsDigit

## Declaration

`Function IsDigit( const S : string) : Boolean`

### Example

```pascal
procedure OnMapEvent(var Value:Variant);
begin
  Value := IsDigit('a'); //returns false
Value := IsDigit('4'); //returns true.
end;
```

## Description

Returns True or False depending on whether the input string is a numeric digit or not. This function only checks the first character in the given string parameter.

Refer [IsNumber](/flow/guide/scripting-reference/functions/numeric/isnumber) for a function that checks a string of multiple characters to determine whether they are all digits.