Loops

New Terminology

loop control variable(s)

One or more variables whose value(s) determine how long the loop will continue.

sentinel (sentinel value)

A value which is used to stop (or continue) loop execution.

flag

A boolean value that flags the end condition of a loop execution

accumulator

A variable that serves to accumulate a series of values.  Usually used in summation, but may be used for any repeated operation.

initialization

For loops, this is the place where we set-up one or more variables that will be used to control loop execution.

decision

For loops, this determines how long the loop will continue to execute.

update

For loops, this step changes the loop control variables to approach the ending condition.

body

For loops, this is the code that may repeatedly execute.

off-by-one error

A looping error in which the control condition causes the loop to execute either one time too many or one time too few.

infinite loop

A looping error in which the control condition is never reached and the loop executes forever until killed by the operating system or the user.

nested loops

Loops contained within other loops.  Some types of problems lend themselves to nesting.

interface

The connection between a driver (or calling) program and the services that it uses

Java Specific Terms

while loop

A precondition loop in java

do while loop

A post condition loop in java

for loop

A precondition, counting loop in java

javadocs

The documentation that is produced from a program with "self documenting" comments

Class notes

1. Review Loops lab
1. LoopDriver.java and Loops.java
2. Look at design of loops, infinite and off by one errors
3. Example of nested loops required to perform a specific task
4. Review Pig and its requirements - how to read the java docs  (how to make javadocs)