This chapter explained routines, which are named pieces of code that other pieces of code can invoke to perform specific tasks. Routines make programming easier and less error-prone by:
Reducing duplicated code
Simplifying complex code
Hiding implementation details
Dividing tasks among programmers
Making debugging easier
The only real drawback to routines is that a routine call requires some overhead. Because they have many advantages and only one small disadvantage, routines are part of most programs.
Writing and using routines is relatively easy. The only really complicated part is understanding how value and reference types behave when you pass them to a routine by value or by reference. Table 9-2 summarizes the combinations.