toDouble function
Implementation
double toDouble(value, {double defaultValue = 0.0}) {
if (value == null) return defaultValue;
if (value is double) return value;
if (value is int) return value.toDouble();
if (value is bool) return value ? 1.0 : 0.0;
if (value is String) return double.tryParse(value) ?? defaultValue;
return defaultValue;
}