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--- guides:programstyle:functions [2020/08/04 15:32] – created wikiadmin
+++ guides:programstyle:functions [2022/08/02 11:59] (current) – external edit 127.0.0.1
@@ Line 26: / Line 26: @@
    cin >> nickName;
    cout << endl;
+</code>
+This code can be simplified through the use of a function:
+<code c++>
+string PromptForString(string prompt) {
+   string tmp;
+   cout << "Enter your " << prompt << " => ";
+   cin >> tmp;
+   cout << endl;
+   return tmp;
+}
+...
+// ask the user for a bunch of name related information
+firstName = PromptForString("First Name");
+lastName = PromptForString("Last Name");
+middleName = PromptForString("Middle Name");
+title = PromptForString("Title");
+nickName = PromptForString("Nickname")
 </code>
@@ Line 31: / Line 50: @@
 ===== Function Length =====
+Functions should be viewable on a single screen.  The programmer should be able to read all, or nearly all of a function at the same time.
+A standard ascii terminal is 24 lines high, so this is a reasonable goal for function length.
+Functions should rarely exceed 50 lines.
 ===== Function Cohesion =====
-===== The main function =====
+There are two aspects of function cohesion:
+   - The code in a function should perform a single well-defined task.
+   - The code in a function should be at the same level of abstraction.
+In the first case, this may be a simple or very complex task but it is a single task.
+In the second case, the program should consist  of either high level (other function calls) or low level (computation, input, ...) actions.  High level routines should read like an algorithm.
+===== The main Function =====
+The main function for most advanced programs should read like an algorithm to solve the main problem.  It should not contain detailed code, but consist of a number of calls to functions.
+A single line main function is not acceptable.
+===== An Example ======