isNumber static method
Implementation
static isNumber(String? value, {bool allowSymbols = true}) {
if (value == null) return false;
var numericRegEx = RegExp(r"^[+-]?([0-9]*[.])?[0-9]+$");
var numericNoSymbolsRegExp = RegExp(r"^[0-9]+$");
if (allowSymbols) {
return numericRegEx.hasMatch(value);
} else
return numericNoSymbolsRegExp.hasMatch(value);
}