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Flow of Control

The flow of control is how a program process instructions.
How do you follow a recipe?
For programs:
- Usually there is some form of main statement where you start.
- Then you follow the instructions in order unless you encounter a control structure or a function call.
- ```
get interest rate from the user
get principal from the user
get time from the user

interest = principal * rate * time
payment = principal + interest

print result 
```
The above is pseudocode or informal high-level descriptions of algorithms and processes.
Control structure:
- A statement that allows the programmer to change the flow of control.

There are two basic types of control structures

selection: if/if else
- called selection because we can "select" one path
- other structures in this class include case/switch
- ```
// Convert the percent to a decimal
if interestRate > 1
   interestRate = interestRate / 100
```

Iteration

Repeat a task until a goal is achieved
repeat, for, while, do while ....

while principal > 0
    // deduct the monthly payment
    principal = principal - monthlyPayment

    // calculate one month interest
    interest = principal*interestRate/12
    principal = principal + interest

Function calls
- Transfer control a different function.
- Functions are just a sequence of program instructions that perform a specific task, packages as a unit.
- Flow of control returns just after the calling point.
- ```
get interest rate from the user
get principal from the user
get time from the user

Call Calculate Results
...
```
Flowcharts
- I mostly do not use flowcharts.
- A flowchart is a diagram that represents an algorithm or process, showing steps as boxes connected by arrows which establish an order of flow.
- In a flowchart
  - A oval is a start/stop of the logic
  - A rectangle represents a task.
  - A triangle represents a decision.
There are numerous tools for producing a flowchart.
I used umlentino
- UML Common Elements has everyone you need.