Fri Oct 15 2021·1 min read
Photo by Kristina Wagner
To get the length of an array, use the
length property. For example,
['a', 'b'].length returns
length property sets or returns the
number of elements in the array. When accessed on an empty array, the
const arr = ['a', 'b', 'c']; console.log(arr.length); // 👉️ 3 console.log(.length); // 👉️ 0
In the examples, we use the Array.length property to get the number of elements the array contains.
length property always returns an integer with a positive sign.
The property can also be set by the user.
Here are examples of truncating an array by setting it's
length property to a
const arr = ['a', 'b', 'c']; arr.length = 1; console.log(arr); // 👉️ ['a'] arr.length = 0; console.log(arr); // 👉️ 
After setting the array's length to
1, only the first element remained in the
0empties the array.
And here is an example of setting an array's length to a higher value.
const arr = ['a']; arr.length = 3; console.log(arr); // 👉️ ['a', , ] console.log(arr.length); // 👉️ 3
After we set the array's length to a higher value, the array got filled with empty elements.
All of the empty elements in the array are non-iterable.
That's because there are specialized methods that allow us to manipulate an array, that work in a more predictable manner.
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