Helpful JavaScript Utilities

helpful-javascript-utilities.js

// zip arrays together
// Catalin Dumitru @colin_dumitru
// Jason Awbrey @jsawbrey
const zip = (a, b) => a.map((n, i) => [n, b[i]])

// merge objects in an array together
// caution: properties are overridden if duplicated
// @a [{a},{b}]
// @returns [{a, b}]
// Jason Awbrey @jsawbrey
const mergeObjsInArray = a => a.reduce((acc, c) => ({...acc, ...c}))

// Partition
// http://colin-dumitru.github.io/functional-programming/javascript/tutorial/2014/12/28/functional_operations_in_es6.html
// Catalin Dumitru @colin_dumitru
var input = [1, 2, "John", 3, "Mike", "Colin"],
  // This predicate separates strings from numbers.
  p = x => x.length;

// This statement
input.reduce(
  (l, r) => ( (p(r) ? l[0] : l[1]).push(r),  l ),
  [[],[]]
);
// Outputs [["John","Mike","Colin"],[1,2,3]]


// Sort array alphabetically
// David Wells @DavidWells
[].sort((a, b) => {
        if (a < b) return -1
        else if (a > b) return 1
        return 0
})

// Sort array reverse alphabetically
// David Wells @DavidWells
[].sort((a, b) => {
        if (a > b) return -1;
        else if (a < b) return 1;
        return 0;
})

// unique array values
// Addy Osmani @addyosmani
const uniqueArray = arr => [ ...new Set(arr) ]

// Immutable Array Operations
// Luke Jackson @lukejacksonn
// Vincent Billey @Fenntasy
const clone = x => [ ...x ]
const push = y => x => [ ...x, y ]
const pop = x => [...x].pop()
const unshift = y => x => [ y, ...x ]
const shift = x => x.slice(1)
const sort = f => x => [...x].sort(f)
const del = i => x => [ ...x.slice(0,i), ...x.slice(i+1) ]
const splice = (s, c, ...y) => x => [ ...x.slice(0,s), ...y, ...x.slice(s+c) ]
const reverse = x => [ ...x ].reverse()

// Filter array by it's truthy values
// arr = [0, '', false, 1].filter(Boolean) // [1]
// Alex Jover Morales @alexjoverm
[].filter(Boolean)


// Make a hash from an array
// @a [{id: uniqueIdA...}, {id: uniqueIdB...}]
// @returns {uniqueIdA: {...}, uniqueIdB: {...}}
// Jason Awbrey @jsawbrey // and probably almost every other dev haha
export const makeHashFromArray = a => a.reduce((acc, curr) => ({...acc, [curr.id]: curr}), {})

// Make array from a hash
// @a {uniqueIdA: {...}, uniqueIdB: {...}}
// @returns [{id: uniqueIdA...}, {id: uniqueIdB...}]
// Jason Awbrey @jsawbrey // and probably almost every other dev haha
export const makeArrayFromHash = a => Object.keys(a).map(x => a[x])