JavaScript - #solve

How can I solve "TypeError: Cannot read property 'x' of undefined" in JavaScript?
How can I solve "SyntaxError: Unexpected end of input" in JavaScript?
How can I solve 'Uncaught TypeError: object is not a function'?
How can I resolve 'Uncaught DOMException: Failed to execute 'querySelector' on 'Document': '' is not a valid selector'?
How to resolve 'SyntaxError: Unexpected token X in JSON' in JavaScript?
How to solve 'SyntaxError: Unexpected string' in JavaScript?