In computer programming, a lint is a piece of software that scans the code and looks for problems. When languages like C and C++ were young, lots of issues where ignored by their primitive compilers. It made sense to use a lint to find bugs statically.
The problems found by these tools are not necessarily syntax errors, although often they are. They also look at some style conventions as well as structural problems. These tools does not prove that your program is correct. They just provide another set of eyes to help spot problems.
Yes I know, sometimes the warnings these tools produce may hurt your feelings but on the long run you will be more productive and your code will be maintainable. With these tools you will be able to avoid plain syntax errors as well as run-time caveats that many of us stumble onto way too often..