Does list implement Iterable?
A List implements the Iterable interface. An Iterator allows you to iterate through a List ‘s elements.
What is an iterable apex?
An iterator traverses through every item in a collection. For example, in a while loop in Apex, you define a condition for exiting the loop, and you must provide some means of traversing the collection, that is, an iterator. Iterators can also be used if you have multiple SELECT statements.
Can you get the length of an iterable?
Absolutely not, for the simple reason that iterables are not guaranteed to be finite. Attempting to calculate the length of this function with len([x for x in forever()]) will clearly not work.
How to implement iterable < T > in Apex code?
Apex Code: Implement Iterable on Set . Currently, we can have custom iterables, and we can coerce a List into a Iterable (because it implements Iterable ). However, we can’t do so for Set , which results in the need for temporary variables and unduly complex code structures.
How is Count incremented in iterator in apex?
In this example, count is incremented by 1 every time the loop is executed. Using the Iterator interface you can create a custom set of instructions for traversing a List through a loop.
How does iterable work in batch apex, Force.com?
You are correct in assuming that you would need two classes: your custom Iteration class plus a batch class that uses that class. Of course, the logic that the Force.com platform uses has greater complexity, including resetting governor limits, etc, but this is the basic design of the Batchable/Iterator interface.
Can You coerce a list into an iterable?
Currently, we can have custom iterables, and we can coerce a List into a Iterable (because it implements Iterable ). However, we can’t do so for Set , which results in the need for temporary variables and unduly complex code structures.