diff --git a/README.md b/README.md index eb58ef8a6..fd9d07be5 100644 --- a/README.md +++ b/README.md @@ -284,8 +284,10 @@ average(1, 2, 3); * [`objectFromPairs`](#objectfrompairs) * [`objectToPairs`](#objecttopairs) * [`omit`](#omit) +* [`omitBy`](#omitby) * [`orderBy`](#orderby) * [`pick`](#pick) +* [`pickBy`](#pickby) * [`shallowClone`](#shallowclone) * [`size`](#size) * [`transform`](#transform) @@ -4500,6 +4502,31 @@ omit({ a: 1, b: '2', c: 3 }, ['b']); // { 'a': 1, 'c': 3 }
[⬆ Back to top](#table-of-contents) +### omitBy + +Creates an object composed of the properties the given function returns falsey for. The function is invoked with two arguments: (value, key). + +Use `Object.keys(obj)` and `Array.filter()`to remove the keys for which `fn` returns a truthy value. +Use `Array.reduce()` to convert the filtered keys back to an object with the corresponding key-value pairs. + +```js +const omitBy = (obj, fn) => + Object.keys(obj) + .filter(k => !fn(obj[k], k)) + .reduce((acc, key) => ((acc[key] = obj[key]), acc), {}); +``` + +
+Examples + +```js +omitBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { b: '2' } + +
+ +
[⬆ Back to top](#table-of-contents) + + ### orderBy Returns a sorted array of objects ordered by properties and orders. @@ -4557,6 +4584,32 @@ pick({ a: 1, b: '2', c: 3 }, ['a', 'c']); // { 'a': 1, 'c': 3 }
[⬆ Back to top](#table-of-contents) +### pickBy + +Creates an object composed of the properties the given function returns truthy for. The function is invoked with two arguments: (value, key). + +Use `Object.keys(obj)` and `Array.filter()`to remove the keys for which `fn` returns a falsey value. +Use `Array.reduce()` to convert the filtered keys back to an object with the corresponding key-value pairs. + +```js +const pickBy = (obj, fn) => + Object.keys(obj) + .filter(k => fn(obj[k], k)) + .reduce((acc, key) => ((acc[key] = obj[key]), acc), {}); +``` + +
+Examples + +```js +pickBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { 'a': 1, 'c': 3 } +``` + +
+ +
[⬆ Back to top](#table-of-contents) + + ### shallowClone Creates a shallow clone of an object. diff --git a/docs/index.html b/docs/index.html index d173421fa..b294be08d 100644 --- a/docs/index.html +++ b/docs/index.html @@ -50,7 +50,7 @@ scrollToTop(); } }, false); - }

logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.

 

Adapter

call

Given a key and a set of arguments, call them when given a context. Primarily useful in composition.

Use a closure to call a stored key with stored arguments.

const call = (key, ...args) => context => context[key](...args);
+      }
logo 30 seconds of code Curated collection of useful JavaScript snippets that you can understand in 30 seconds or less.
 
Adapter
call
Given a key and a set of arguments, call them when given a context. Primarily useful in composition.
Use a closure to call a stored key with stored arguments.
const call = (key, ...args) => context => context[key](...args);
 
Promise.resolve([1, 2, 3])
   .then(call('map', x => 2 * x))
   .then(console.log); //[ 2, 4, 6 ]
@@ -1010,6 +1010,11 @@ Foo.prototypefilter(k => !arr.includes(k))
     .reduce((acc, key) => ((acc[key] = obj[key]), acc), {});
 
omit({ a: 1, b: '2', c: 3 }, ['b']); // { 'a': 1, 'c': 3 }
+
omitBy
Creates an object composed of the properties the given function returns falsey for. The function is invoked with two arguments: (value, key).
Use Object.keys(obj) and Array.filter()to remove the keys for which fn returns a truthy value. Use Array.reduce() to convert the filtered keys back to an object with the corresponding key-value pairs.
const omitBy = (obj, fn) =>
+  Object.keys(obj)
+    .filter(k => !fn(obj[k], k))
+    .reduce((acc, key) => ((acc[key] = obj[key]), acc), {});
+
omitBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { b: '2' }
 
orderBy
Returns a sorted array of objects ordered by properties and orders.
Uses Array.sort(), Array.reduce() on the props array with a default value of 0, use array destructuring to swap the properties position depending on the order passed. If no orders array is passed it sort by 'asc' by default.
const orderBy = (arr, props, orders) =>
   [...arr].sort((a, b) =>
     props.reduce((acc, prop, i) => {
@@ -1026,6 +1031,11 @@ Foo.prototype📋 Copy to clipboard
pick
Picks the key-value pairs corresponding to the given keys from an object.
Use Array.reduce() to convert the filtered/picked keys back to an object with the corresponding key-value pairs if the key exists in the object.
const pick = (obj, arr) =>
   arr.reduce((acc, curr) => (curr in obj && (acc[curr] = obj[curr]), acc), {});
 
pick({ a: 1, b: '2', c: 3 }, ['a', 'c']); // { 'a': 1, 'c': 3 }
+
pickBy
Creates an object composed of the properties the given function returns truthy for. The function is invoked with two arguments: (value, key).
Use Object.keys(obj) and Array.filter()to remove the keys for which fn returns a falsey value. Use Array.reduce() to convert the filtered keys back to an object with the corresponding key-value pairs.
const pickBy = (obj, fn) =>
+  Object.keys(obj)
+    .filter(k => fn(obj[k], k))
+    .reduce((acc, key) => ((acc[key] = obj[key]), acc), {});
+
pickBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { 'a': 1, 'c': 3 }
 
shallowClone
Creates a shallow clone of an object.
Use Object.assign() and an empty object ({}) to create a shallow clone of the original.
const shallowClone = obj => Object.assign({}, obj);
 
const a = { x: true, y: 1 };
 const b = shallowClone(a); // a !== b