This tutorial explains how to do the sum of array numbers in Ruby.

- Sum of array numbers
- Sum of numbers between a and b

## Ruby sum of array numbers with an example

There are a number of ways we can calculate the sum of an array of numbers in Ruby

- sum method
- reduce method
- inject method

### sum method

The `sum`

method is only available in the Ruby 2.4 version onwards.
It returns the sum of all elements. It returns 0 if the array is empty.
It added an enumerable type and was used with Arrays.

If the array is a string, It returns by appending all elements.

Here is an example

```
numbers = [1,2,3,4]
result = numbers.sum
puts "#{result}"
result1=0
numbers.sum {|item| result1+=item }
puts "#{result1}"
result2=numbers.sum {|item| item }
puts "#{result2}"
```

Output

```
10
10
10
```

### reduce method

```
numbers = [1,2,3,4,5]
result=numbers.reduce(0, :+)
puts "#{result}"
result1=numbers.reduce(:+)
puts "#{result1}"
```

Output

```
10
```

### inject method

`inject`

method combine all elements with a given binary operation.

inject and reduce functions behavior are the same. used with the below ruby 2.4 version only.

Here is an example

```
numbers = [1,2,3,4,5]
result=numbers.inject(0, :+)
puts "#{result}"
result1=numbers.inject(:+)
puts "#{result1}"
```

## Sum of numbers between two numbers in Ruby

For example, Two numbers are 1, 10. This program returns the sum of all numbers from 1 to 10.

```
def sum(first,second)
first, second = second, first if first > second
return (first..second).sum
end
print sum(1,10)
```

Output:

```
55
```

## Conclusion

Learned multiple ways to sum of array numbers, between two numbers in Ruby and rails language.