1. All loops require what feature to 
ensure that the looping will eventually end and not 
result in an infinite loop?

Exit condition


2. What four looping structures are used in PHP?

While, Do...While for. foreach

3. Explain the purpose of a "counter" variable when excuting a loop.


usually it counts until it is time to exit. 

4. Which type of looping structure is used to iterate 
through elements of an array? 

foreach