Hello, My Code passed Every test but one the extra test,even though i tested it in visual studio and it works fine, i used c#,here is the issue:
Extra Tests
Test Failed
String lengths are both 46. Strings differ at index 21.
Expected: "wha1t sh2all 3we d4o w5ith a6 dru7nken s8ailor"
But was: "wha1t sh2all 3we d4o a6 w5ith dru7nken s8ailor"
-how can i fix it?

Thank You Very Much

sorry about that, here is the errors im getting regarding the problem :
src/Solution.cs(10,17): error CS1061: 'char' does not contain a definition for 'isLower' and no accessible extension method 'isLower' accepting a first argument of type 'char' could be found (are you missing a using directive or an assembly reference?)
src/Solution.cs(11,29): error CS1501: No overload for method 'ToUpper' takes 0 arguments
src/Solution.cs(12,25): error CS1061: 'char' does not contain a definition for 'isUpper' and no accessible extension method 'isUpper' accepting a first argument of type 'char' could be found (are you missing a using directive or an assembly reference?)

why Char methods dont work in here

thank you very much.

u mean using System its there but for some reason its not detecting the array Methods

why i cant use array methods in here?, im using C#.