How to sum the values of multiple items in a JavaScript object?

I’d like to sum the values of multiple objects.

I have an array of example 3 items, this varies and can be any number.

_items: 
0: {...}
1: {...}
2: {...}

Each of these item then has the following data:

0: 
dayOfYear: 357
dayOfWeek: 4
noOfUnits: "11"
_id: "12345"
_owner: "12345"
_createdDate: "Thu Dec 23 2021"
year: 2021
_updatedDate: "Thu Dec 23 2021"
week: 51
userId: "12345"
type: "Type 1"

I’d like to add the values of the noOfUnits variable. So for example in item 0 value is 11, item 1 is 2 and item 2 is 5. The total would become 18. This is not limited to 3 items but varies according to the number of items pulled from a database.

Thanks and happy holidays!