type 'String' is not a subtype of type 'int'

Why This Happens

In Dart, types are strict and implicit conversions do not happen. This commonly occurs when JSON data contains a number as a string (e.g., "42" instead of 42) but the Dart code expects an int. Use int.parse() or int.tryParse() for conversion.

The Problem

final json = {'count': '42'};
final int count = json['count']; // String is not int

The Fix

final json = {'count': '42'};
final int count = int.parse(json['count']);

Step-by-Step Fix

1. 1

   Identify the error

   Look at the error message: type 'String' is not a subtype of type 'int'. This means a String was assigned where an int was expected.

2. 2

   Find the cause

   Check JSON responses or dynamic data where numbers might be represented as strings.

3. 3

   Apply the fix

   Use int.parse() or int.tryParse() for safe conversion, and handle potential FormatException.