array-differences
Find the differences between two arrays and their positions.
Installation
npm install array-differences --save
or
yarn add array-differences
Usage
import arrayDifferences from 'array-differences'
const input = [0, 1, 1, 4, 1, 1]
const output = [111, 1, 112, 1, 4, 1]
const diff = arrayDifferences(input, output)
--> [['modified', 0, 111], ['inserted', 2, 112], ['deleted', 5]]
Using a custom comparison function:
const diff = arrayDifferences(
[{ name: 'John' }, { name: 'Marie' }],
[{ name: 'John' }, { name: 'Marie' }, { name: 'Chloe' }],
(a, b) => a.name === b.name
)
--> [['inserted', 2, { name: 'Chloe' }]]
You can recontruct the second array by iterating over the differences on the first array or using the utility:
import { reconstructArray } from 'array-differences'
const reconstructed = reconstructArray(input, diff) // builds the output
// You can reconstruct in place:
reconstructArray(input, diff, true) // modifies input to recreate output from diff
Undefined values
The algorythm does not support arrays containing undefined
values. Please replace your undefined
values with a placeholder before applying it.
Performance on large arrays
Entry one is length n,
Entry two is length m,
Perfomance is n * n * m.
Therefore, it works best on smaller first arrays or if growing an array. Performance is best when differences indexes are close to one another in the array.
License
MIT