array.fetch()
or fetch()
is a Ruby function that is used to find and return an element based on the index passed to the fetch()
function or method.
array.fetch([n])
n
: This is the index of the element to fetch.The element with the index position specified is returned.
In the example below, we create arrays and use the fetch()
method to find and return some of their elements.
# create arraysarray1 = [1, 2, 3, 4, 5]array2 = ["a", "b", "c", "d", "e"]array3 = ["Python", "Ruby", "Java"]array4 = [true, false, nil, 0, 1]# fetch some elements of arrays abovea = array1.fetch(0)b = array2.fetch(4)c = array3.fetch(1)d = array4.fetch(3)# print values returnedputs "#{a}"puts "#{b}"puts "#{c}"puts "#{d}"
Passing a negative index position means that counting starts from -1
and this is the last element in the array.
See the example below:
# create an arrayarray = [1, 2, 3, 4, 5]# use the fetch() methoda = array.fetch(-2) # fetch second element from the lastb = array.fetch(200) # index out of bound# print value of elementputs "#{a}"puts "#{b}"
Note that fetching an array by an index that is out of bounds results in an error.
See the example code below:
# create an arrayarray = [1, 2, 3, 4, 5]# use the fetch() methoda= array.fetch(200) # index out of bound# print value of elementputs "#{a}" # throws an error