What do the exclamation marks mean?
In an IDE (Integrated Development Environment), exclamation marks often denote an error or warning. Depending on the context and the particular IDE being used, the precise meaning may change. For instance, an exclamation mark next to a line of code in one IDE can mean that the code has a syntax error and won’t run, whereas in another it might mean that the code has a possible issue but will still run. It is best to go to the documentation or support materials for your particular IDE to determine what exclamation points signify in your situation. However, here it is warning only.
I see. Thank you for the clear explanation.