Summing values in an array using the inject method

In this section, I'm going to examine how to sum up values in Ruby by implementing the inject method. Being able to sum up values in an array is something you will most likely need in a number of different situations. Thankfully, Ruby makes this very straightforward to implement.

Before we see how to implement the inject method, I think it's beneficial to review how to generate a sum manually:

total = 0 

[3, 2, 4, 53, 5, 3, 23343, 4342, 12, 3].each do |i| 
  total += i 
end 

puts total 

When you run this program, it will generate the value 27700, which is the sum of all the individual values present in the array.

However, that took four lines of code. To shorten it, we can use the inject method:

[3, 2, 4, 53, 5, 3, 23343, 4342, 12, 3].inject(&:+) 

In this code, we are calling the inject method and passing it to each element in the array. The inject method is similar to map or select in the way that it looks at each element in a collection...