@b08/array, seeded from @b08/library-seed, library type: dry
Set of DRY functions to work with array. Typescript style.\
Why not lodash? lodash is heavy, this package is light as air. \
And supports es5/es6/esnext in compile time, i.e. a bit more efficient code in node and chrome without runtime checks for platform.\
To use it with ES5, import it as "@b08/array/es5"
all
Method returns true if all items in the array fulfill the condition. Empty array also yields true.
``
import { all } from "@b08/array"
const a = [1, 2, 3];
const allHigher = all(a, item => item > 2); // false
const allNumbers = all(a, isNumber); // true
`
areEqual
Method returns true if two arrays are equal by criteria, and go in the same order.
`
const a = [
{ id: 1, name: 'a' },
{ id: 2, name: 'b' }
];
const b = [
{ id: 1, name: 'c' },
{ id: 2, name: 'd' }
];
const c = [
{ id: 2, name: 'b' },
{ id: 1, name: 'a' }
];
const anb = areEqual(a, b, item => item.id); // true
const anc = areEqual(a, c, item => item.id); // false
`
areEquivalent
Method returns true if two arrays are equal by criteria, order does not matter.
contains
Returns true if item is present in the array. Useful if array.prototype.includes is not available
intersect and except
intersect returns items present in both arrays, except return items from first array not present in second array
`
const a = [1, 2];
const b = [2, 3];
const result1 = intersect(a, b); // [2]
const result2 = except(a, b); // [1]
`
flatMap
Combination of map and then flatten, aka concatenation of array of arrays.
const a = [1, 2];
const b = flatMap(a, item => [item, 3]); // [1, 3, 2, 3];
hasElements
Returns true if array is an instance of Array and contains at least one element
first and last
Returns first and last elements of array satisfying the criteria, or undefined if no such elements present.
`
const a = [1, 2, 3];
const result1 = first(a, item => item > 1); // 2
const result2 = last(a, item => item > 1); // 3
`
min and max
Returns element minimal or maximal by given criteria
`
const a = [1, 2, 3];
const result1 = min(a, item => -item); // 3
const result2 = max(a, item => -item); // 1
`
regexToArray
Current interface of working with /g regex is a bit inconvenient. This method transforms it to array of matches. So you can execute .map on it and etc.
`
const matches = regexToArray(/\d/g, 'a1b2c');
// two matches, matches[0][0] = '1', matches[1][0] = '2'
splitInGroups
Splits array into a provided number of arrays
`
const a = [1, 2, 3, 4, 5, 6];
const result = splitInGroups(a, 2); // [[1, 2, 3], [4, 5, 6]];
splitInGroupsBy
Splits array into arrays of given size
`
const a = [1, 2, 3, 4, 5, 6];
const result = splitInGroups(a, 2); // [[1, 2], [3, 4], [5, 6]];
unique
Returns items from array unique by given criteria
`
const a = [
{ id: 1, name: 'a' },
{ id: 1, name: 'b' },
{ id: 2, name: 'c' },
{ id: 2, name: 'd' }
];
const result = unique(a, item => item.id); // [a[0], a[2]]
`
range
Returns array of numbers from start(inclusive) to end(non-inclusive)
trim
Removes amount of items from end of the array, one by default.
``
const items = [1, 2, 3, 4];
const result = trim(items, 2); // [1, 2]