$isdigit

Tests if a character string contains only digits.

$isdigit(string)

string

a character string or an expression that evaluates to a character string

1-character binary string. Evaluates to 1 ($True) if string meets the validation test; otherwise, evaluates to 0 ($False).

This function tests if a particular character string is all digits.

$isdigit("0123")

Evaluates to $True.

$isdigit(2.3)

Evaluates to $False.