[Solved] FormatException: Invalid double Error in Flutter

In this post, we are going to show you how to solve the "FormatException: Invalid double" error that occurred on Flutter or Dart. This error occurs when you are doing double.parse() with the invalid source of the string.

Error Message:

══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞══════
The following FormatException was thrown building Builder:
Invalid double

Cause of Error:

This error occurs, when you are putting an invalid string format to double.parse().

Solution of Error:

To solve this error, you can extract the double numbers from the string using Regex, and then double.parse() it. For Example:

String str = "Hafce00453dfg23.4fdksd";
double newdbl = double.parse(str.replaceAll(RegExp(r'[^0-9.]'),''));
print(newdbl);// output: 45323.4

//if there is no dot
String str1 = "Hafce00453dfg234fdksd";
double newdbl1 = double.parse(str1.replaceAll(RegExp(r'[^0-9.]'),''));
print(newdbl1);// output: 453234.0

Here, we extract the double from the string and then parse it to double. 

In this way, you can solve "FormatException: Invalid double" error in Flutter or Dart.