how to fix double in flutter even if the last decimal is 0

Hi so i have a double seems like this

d1 = 12.106

and i need to show in to a string ‘12.130’

 double num1 = double. parse((12.3404). toStringAsFixed(3));

well i expected to return "12.130" but it returned "12.13"

the thing i need a string "12.130" instead "12.13"

 double num1 = double. parse((12.3404). toStringAsFixed(4));

so tried this one again but also failed

well then number must be shown 3 decimals even if the last is 0

where or what should i have to fix?

>Solution :

I understand you have the following variable:
double d = 12.130;

and now you want to convert it to a string with the following value: String s = "12.130"

This should work:
String res = d.toStringAsFixed(3) //"12.130"