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How to count Ruby Array items

By Flatiron SchoolDecember 18, 2012

The following is a guest post by Rex Feng and originally appeared on his blog. Rex is currently a student a The Flatiron School. You can learn more about him here, or follow him on twitter here.

While working in Ruby, I often find myself trying to get a count of the number of times each item appears in an array. Below, I’ll show you how to create a Hash that iterates through each item in the array and counts the number of occurrences.

We have an array of animals that we want to count.

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We can count them up by creating a new Hash.

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Next, we want to iterate through the animals Array and set the animal_count Key as the animal name & the animal_count Value as the counter.

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For each animal in animals, we’ve either created a new Key / Value pair in animal_count or incremented the Value corresponding to the animal Key.

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