上游充通大 ParisTech SHANGHAI JIAO TONG UNIVERSITY INSTITUT DES SCIENCES ET TECHNOLOGIES PARIS INSTITUTE OF TECHNOLOGY Functions,Informally A function is like a subprogram,a small program inside of a program. The basic idea-we write a sequence of statements and then give that sequence a name.We can then execute this sequence at any time by referring to the name. 55 Functions, Informally • A function is like a subprogram, a small program inside of a program. • The basic idea – we write a sequence of statements and then give that sequence a name. We can then execute this sequence at any time by referring to the name