Which kind of DO loop executes a set of statements based on the current value of an index variable?

The iterative DO loop is designed to execute a set of statements a specific number of times, based on the current value of an index variable. This type of loop enables the programmer to control the number of iterations through the use of an index, which often starts at a defined value and increments or decrements according to a specified step size.

For example, if an index variable is set to start at 1 and continues to increment until it reaches a limit, the iterative DO loop will specifically execute its block of statements for each value of the index variable within that defined range. This structure facilitates repetitive tasks and simplifies code for scenarios where the number of iterations is predetermined.

In contrast, loops like DO WHILE and DO UNTIL are conditional loops that continue execution based on whether a specified condition is true or false, rather than on an index variable's current value. These types of loops do not have a fixed number of iterations determined by an index, and instead rely on the evaluation of conditions during execution. The DO END option is not a standalone loop type but rather a way to denote the beginning and end of a block of statements in SAS.

Therefore, the iterative DO loop is particularly effective for situations requiring a definite sequence of iterations governed by an index