What does inject in ruby do
Explanation of the inject
method in Ruby:
The inject
method in Ruby is used to accumulate a value by applying a binary operation to each element in a collection. It is also known as reduce
in other programming languages. The inject
method takes an initial value and a block as arguments. The block specifies the operation to be performed on each element of the collection.
Here is a step-by-step explanation of how the inject
method works:
- The
inject
method is called on a collection (e.g., an array) and takes an initial value as an argument. - The initial value is assigned to a variable, often referred to as the accumulator.
- The block is executed for each element in the collection.
- The block takes two arguments: the accumulator and the current element of the collection.
- The block performs an operation on the accumulator and the current element, and the result is assigned back to the accumulator.
- The updated accumulator is then used in the next iteration of the block.
- After all iterations are completed, the final value of the accumulator is returned as the result of the
inject
method.
Here is an example to illustrate the usage of the inject
method:
numbers = [1, 2, 3, 4, 5]
sum = numbers.inject(0) { |accumulator, number| accumulator + number }
puts sum
In this example, the inject
method is called on the numbers
array with an initial value of 0. The block adds each element of the array to the accumulator, starting from the initial value of 0. The final result is the sum of all the numbers in the array, which is printed as output.
Note: The inject
method can also be used without an initial value. In that case, the first element of the collection is used as the initial value, and the block is executed starting from the second element.