The C standard library provides numerous built-in functions that your program can call. For example, strcat() to concatenate two strings, memcpy() to copy one memory location to another location, and many more functions. A function can also be referred as a method or a sub-routine or a procedure, etc.
Quick Answer. Authors use repetition for several reasons, including making a point, to set a rhythm, link topics or ideas and to make discussions easier to follow. Using repetition in writing is something that still has rules and should be used with some thought instead of randomly.
The more you hear a jingle, the greater the chance it will stick in your mind. Repetition is important in advertising, because customers often go with a familiar brand or name. If the jingle gets stuck in a person's mind, your company does not even need to run ads for the jingle to reinforce your brand name.