Array elements can be not only strings and numbers, but also arrays. In this case, we get an array of arrays, or a multidimensional array.
In the following example, the array arr
consists of three elements, which
in turn are arrays:
let arr = [['a', 'b', 'c'], ['d', 'e', 'f'], ['g', 'h', 'i']];
Let's rewrite in a more understandable way:
let arr = [
['a', 'b', 'c'],
['d', 'e', 'f'],
['g', 'h', 'i'],
];
Depending on the level of nesting, arrays can be two-dimensional - an array of arrays, three-dimensional - an array of arrays of arrays (and so on - four-dimensional, five-dimensional, etc.).
The above array is two-dimensional, since there are other sub-arrays inside one array, and there are no other arrays already in these sub-arrays.
To display any element from a two-dimensional array, you should write not one pair of square brackets, but two:
let arr = [
['a', 'b', 'c'],
['d', 'e', 'f'],
['g', 'h', 'i'],
];
console.log(arr[0][1]); // shows 'b'
console.log(arr[1][2]); // shows 'f'
Given the following array:
let arr = [
['a', 'b', 'c'],
['d', 'e', 'f'],
['g', 'h', 'i'],
['j', 'k', 'l'],
];
Use it to output elements with the text
'l'
, 'e'
, 'g'
and 'a'
Given the following array:
let arr = [[1, 2], [3, 4], [5, 6]];
Referring to each array element, find the sum of all its elements.