Find value in an array

Question

In Ruby, how can I find a value in an array?

Answer 1

Use:

myarray.index "valuetoFind"

That will return you the index of the element you want or nil if your array doesn't contain the value.

Answer 2

If you want find one value from array, use Array#find:

arr = [1,2,6,4,9] 
arr.find {|e| e%3 == 0}   #=>  6

See also:

arr.select {|e| e%3 == 0} #=> [ 6, 9 ]
e.include? 6              #=> true

To find if a value exists in an Array you can also use #in? when using ActiveSupport. #in? works for any object that responds to #include?:

arr = [1, 6]
6.in? arr                 #=> true

Answer 3

This answer is for everyone that realizes the accepted answer does not address the question as it currently written.

The question asks how to find a value in an array. The accepted answer shows how to check whether a value exists in an array.

There is already an example using index, so I am providing an example using the select method.

1.9.3-p327 :012 > x = [1,2,3,4,5]
  => [1, 2, 3, 4, 5] 
1.9.3-p327 :013 > x.select {|y| y == 1}
  => [1]

Answer 4

You can go for array methods.

To see all array methods use methods function with array. For Example,

a = ["name", "surname"] 
a.methods

By the way you can use different method for checking value in array You can use a.include?("name").