Patrick O'Hara questions

Patrick O'Hara answers

• The argument type 'Object?' can't be assigned to the parameter type 'String'
• Flutter FlatButton is deprecated - alternative solution with width and height
• Flutter Error: The body might complete normally, causing 'null' to be returned, but the return type is a potentially non-nullable type
• Error: The argument type 'String?' can't be assigned to the parameter type 'String' because 'String?' is nullable and 'String' isn't [duplicate]