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Ruby include: Array Contains Method

Determine if an array contains a value by searching it with the include method.
Include, array. Does an array contain a specific value? With Ruby we can use a loop or an iterator to search an array. But another approach can be used.While, UntilIterator
With include, we can search an array for a value in a single method call. This is easier to read and easy to use. We must include a question mark at the end of include.
An example. Let us begin. This program uses an array of 3 integers. It then searches the array with "include?" 2 times. The first tested value, 200, is found.Array

And: The include method returns true if a value if found. If a value is not found, it returns false.

Next: The program searches the "values" array for 999, which is not found. It prints a helpful message.

Ruby program that uses include method on array values = [10, 200, 3000] # See if array includes this value. if values.include?(200) puts "ARRAY CONTAINS 200" end # See if array does not include this value. if !values.include?(999) puts "ARRAY DOES NOT CONTAIN 999" end Output ARRAY CONTAINS 200 ARRAY DOES NOT CONTAIN 999
Some notes. In Ruby, a method that ends in a question mark is a predicate method, one that returns true or false. With "include we get a boolean result.
A summary. Methods that use iterators usually will involve more code than "include?." But they also may be more powerful—you can add more steps to the iterator than you can to "include."
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