Question

I’ve got arrays nested like this:

[["1", "apple 1"], ["1", "pear 2"], ["2", "lemon 1"], ["12", "lemon 12"]]

I’d like to replace all the occurrences of 1, 2, and 12 at nested array index 0 with "one", "two", and "twelve" respectively, so the result is this:

[["one", "apple 1"], ["one", "pear 2"], ["two", "lemon 1"], ["twelve", "lemon 12"]]

How do I do it?

Answer 1

var arr = [
    [ '1', 'apple 1' ], [ '2', 'pear 2' ], [ '3', 'lemon 3' ]
]

var numbers = [ 'one', 'two', 'three' ]

arr.forEach(function (el) {
    el[0] = numbers[el[0]]
})

arr // [ [ 'one', 'apple 1' ], [ 'two', 'pear 2' ], [ 'three', 'lemon 3' ] ]

Array indexes are actually strings, that’s why numbers['2'] ('2' being a string) would retrieve the third member.

To iterate over the array, you could use a for-loop, but forEach looks nicer.