I guess you mean predefined functions or library functions. Well, you don't have to use them, but they can be useful.
I don't use that function in C programme.
Yes
C. Kolstad has written: 'Electric Utility Oil and Gas Use in the Eighties'
ATK_Hotkey Utility: This is required to make use of all the function key shortcuts.
This function is obsolete. Do not use it.
Yes, I did.
Because if you donot use main function in c program, the compiler willnot execute the program.C compiler starts execution from main function itself.
The importances of law of diminishing marginal utility are given below: a) use in consumption b) use in production c) use in exchange d) use in distribution e) use in public finance.
TLINK is the Turbo C++ linker utility. You use it to link the object files created by the Turbo C++ compiler.
By function
Function
To specify the return-type of the function.