Add omitBy, pickBy

snippets/omitBy.md

@@ -0,0 +1,16 @@
+### 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), {});
+```
+
+```js
+omitBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { b: '2' }

snippets/pickBy.md

@@ -0,0 +1,17 @@
+### 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), {});
+```
+
+```js
+pickBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'); // { 'a': 1, 'c': 3 }
+```

tag_database

@@ -132,6 +132,7 @@ objectToPairs:object,array
 observeMutations:browser,event,advanced
 off:browser,event
 omit:object,array
+omitBy:object,array,function
 on:browser,event
 once:function
 onUserInputChange:browser,event,advanced
@@ -141,6 +142,7 @@ parseCookie:utility,string
 partition:array,object,function
 percentile:math
 pick:object,array
+pickBy:object,array,function
 pipeFunctions:adapter,function
 pluralize:string
 powerset:math