Rename js snippets

snippets/js/s/combine-object-arrays.md

@@ -0,0 +1,45 @@
+---
+title: Combine object arrays
+type: snippet
+language: javascript
+tags: [array,object]
+author: chalarangelo
+cover: digital-nomad-6
+dateModified: 2020-10-08T02:22:39+03:00
+---
+
+Combines two arrays of objects, using the specified key to match objects.
+
+- Use `Array.prototype.reduce()` with an object accumulator to combine all objects in both arrays based on the given `prop`.
+- Use `Object.values()` to convert the resulting object to an array and return it.
+
+```js
+const combine = (a, b, prop) =>
+  Object.values(
+    [...a, ...b].reduce((acc, v) => {
+      if (v[prop])
+        acc[v[prop]] = acc[v[prop]]
+          ? { ...acc[v[prop]], ...v }
+          : { ...v };
+      return acc;
+    }, {})
+  );
+```
+
+```js
+const x = [
+  { id: 1, name: 'John' },
+  { id: 2, name: 'Maria' }
+];
+const y = [
+  { id: 1, age: 28 },
+  { id: 3, age: 26 },
+  { age: 3}
+];
+combine(x, y, 'id');
+// [
+//  { id: 1, name: 'John', age: 28 },
+//  { id: 2, name: 'Maria' },
+//  { id: 3, age: 26 }
+// ]
+```