This is the best website, which has over millions of code snippets, solutions to the problems posted by many programmers.
It is a single platform to solve your problem in programming languages like c, c+ , java, bash, php, c#, html etc. and to teach you with the solution.
As it is already established website many of the situations you get error while executing your program are already solved by professionals with the solutions attached in the thread.
When I used to work in a startup company, I used face some problems while executing my code with new errors which I had never heard off. But then one of colleague suggested me to lookup at stackoverflow.com, from then I visit stackoverflow whenever I face any problems or errors which may be compile time or run time error, stackoverflow has the answer.