Add functions, functionsIn

snippets/functions.md

@@ -0,0 +1,18 @@
+### functions
+
+Returns an array of function property names from own enumerable properties of object.
+
+Use `Object.keys(obj)` to iterate over the object's own properties, `Array.filter()` to keep only those that are functions.
+
+```js
+const functions = obj =>
+  Object.keys(obj).filter(key => typeof obj[key] === 'function');
+```
+
+```js
+function Foo() {
+  this.a = () => 1;
+  this.b = () => 2;
+}
+functions(new Foo); // ['a', 'b']
+```

snippets/functionsIn.md

@@ -0,0 +1,20 @@
+### functionName
+
+Returns an array of function property names from own and inherited enumerable properties of object.
+
+Use `Object.keys(obj)` and `Object.get.PrototypeOf(obj)` to iterate over the object's own and inherited properties, `Array.filter()` to keep only those that are functions.
+Use the spread operator (`...`) to combine all returned property names into one array.
+
+```js
+const functionsIn = obj =>
+  [...Object.keys(obj), ...Object.keys(Object.getPrototypeOf(obj))].filter(key => typeof obj[key] === 'function');
+```
+
+```js
+function Foo() {
+  this.a = () => 1;
+  this.b = () => 2;
+}
+Foo.prototype.c = () => 3;
+functionsIn(new Foo); // ['a', 'b', 'c']
+```

tag_database

@@ -51,6 +51,8 @@ forEachRight:array,function
 formatDuration:date,math,string,utility
 fromCamelCase:string
 functionName:function,utility
+functions:object,function
+functionsIn:object,function
 gcd:math,recursion
 geometricProgression:math
 getDaysDiffBetweenDates:date