ABSTRACT
This chapter covers iteration control structures, in which a statement or block is executed until the program reaches a certain state, or operations have been applied to every element of a set. Such structures are initiated with keywords such as while, repeat, for or do..until. Because iteration of this kind can be visualised as a circular loop, the structures are often referred to as “loops”. Iteration can be accomplished with test before loops, test after loops, and counting loops.
