Travis build: 1213

README.md

@@ -266,6 +266,7 @@ average(1, 2, 3);
 * [`lowercaseKeys`](#lowercasekeys)
 * [`mapKeys`](#mapkeys)
 * [`mapValues`](#mapvalues)
+* [`merge`](#merge)
 * [`objectFromPairs`](#objectfrompairs)
 * [`objectToPairs`](#objecttopairs)
 * [`orderBy`](#orderby)
@@ -4071,6 +4072,46 @@ mapValues(users, u => u.age); // { fred: 40, pebbles: 1 }
 <br>[⬆ Back to top](#table-of-contents)
 
 
+### merge
+
+Creates a new object from the combination of two or more objects.
+
+Use `Array.reduce()` combined with `Object.keys(obj)` to iterate over all objects and keys.
+Use `hasOwnProperty()` and `Array.concat()` to append values for keys existing in multiple objects.
+
+```js
+const merge = (...objs) =>
+  [...objs].reduce(
+    (acc, obj) =>
+      Object.keys(obj).reduce((a, k) => {
+        acc[k] = acc.hasOwnProperty(k) ? [].concat(acc[k]).concat(obj[k]) : obj[k];
+        return acc;
+      }, {}),
+    {}
+  );
+```
+
+<details>
+<summary>Examples</summary>
+
+```js
+const object = {
+  a: [{ x: 2 }, { y: 4 }],
+  b: 1
+};
+const other = {
+  a: { z: 3 },
+  b: [2, 3],
+  c: 'foo'
+};
+merge(object, other); // { a: [ { x: 2 }, { y: 4 }, { z: 3 } ], b: [ 1, 2, 3 ], c: 'foo' }
+```
+
+</details>
+
+<br>[⬆ Back to top](#table-of-contents)
+
+
 ### objectFromPairs
 
 Creates an object from the given key-value pairs.

snippets/merge.md

@@ -10,9 +10,7 @@ const merge = (...objs) =>
   [...objs].reduce(
     (acc, obj) =>
       Object.keys(obj).reduce((a, k) => {
-        acc[k] = acc.hasOwnProperty(k)
+        acc[k] = acc.hasOwnProperty(k) ? [].concat(acc[k]).concat(obj[k]) : obj[k];
-          ? [].concat(acc[k]).concat(obj[k])
-          : obj[k];
         return acc;
       }, {}),
     {}
@@ -22,12 +20,12 @@ const merge = (...objs) =>
 ```js
 const object = {
   a: [{ x: 2 }, { y: 4 }],
-  b: 1,
+  b: 1
 };
 const other = {
   a: { z: 3 },
   b: [2, 3],
-  c: 'foo',
+  c: 'foo'
 };
 merge(object, other); // { a: [ { x: 2 }, { y: 4 }, { z: 3 } ], b: [ 1, 2, 3 ], c: 'foo' }
 ```