array-select

🚬 Extract items from one array into two or more arrays by results of a provided function

const arraySelect = require('array-select');

const [odd, even] = arraySelect(
    [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
    i => i % 2
);

Arguments

const results = arraySelect(Array, Function[, ...Functions]);

Functions accept three parameters (just like all array iterator functions):

• element {Any}: The current element being processed in the array
• index {Number} : The index of the current element being processed in the array.
• array {Array} The array being processed

The function should return a truthy or falsy value (coerced into a boolean for testing purposes)

Passing one function will create two arrays

const [odd, even] = arraySelect(
    [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
    i => i % 2
);

odd  // [1, 3, 5, 7, 9]
even // [2, 4, 6, 8, 10]

Passing more than one function will result in same number of arrays. Elements can be included in more than one result array

const [adult, male] = arraySelect(
    [
        {gender: 'male', age: 8},
        {gender: 'male', age: 64},
        {gender: 'female', age: 14},
        {gender: 'male', age: 21},
        {gender: 'female', age: 32},
    ],
    ({age}) => age > 18,
    ({gender}) => gender === 'male',
);

adult // [{gender: 'male', age: 64}, {gender: 'male', age: 21}, {gender: 'female', age: 32}]
male  // [{gender: 'male', age: 8}, {gender: 'male', age: 64}, {gender: 'male', age: 21}]

A callback function that uses more arguments

const [original, duplicates] = split(
    [1, 1, 2, 3, 4, 1, 3, 8],
    (item, index, array) => index === array.indexOf(item)
);

original   // [1, 2, 3, 4, 8]
duplicates // [1, 1, 3]

Transpiled version

Environments which exclude node_modules from the transpiling pipeline should include the "browser" entry instead of "main". This exposes an ES5 commonjs module.

Also available for explicit import:

const arraySelect = require('array-select/dist');