I notice that functions like printf() and toupper() appear in blue without the relevant #include statements in files with names ending in .c. What is happening under the hood to make this happen?

1 Answer 1


The IDE has been programmed to know all the common libraries used (stdio, stdlib,etc.) and to highlight the function names in all the common libraries, just like it knows all c keywords.

Think about it. How useful would the IDE be if it didn't know about things like printf? The devs knew what was needed. ;-)

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