difference between each.with_index and each_with_index in Ruby?

Question

I\'m really confused about the difference between each.with_index and each_with_index. They have different types but seem to be identical in practi

Answer 1

each_with_index was introduced into Ruby earlier. with_index was introduced later:

1. to allow wider usage with various enumerators.
2. to allow index to start from a number other than 0.

Today, using with_index would be better from the point of view of generality and readability, but from the point of view of speeding up the code, each_with_index runs slightly faster than each.with_index.

When you feel that a single method can be easily expressed by straightforward chaining of a few methods, it is usually the case that the single method is faster than the chain. As for another example of this, reverse_each runs faster than reverse.each. These methods have reason to exist.