Similarity between arrays, object from key-value pairs

snippets/difference-between-arrays.md

@@ -1,6 +1,6 @@
 ### Difference between arrays
 
-Use `filter()` to remove values that are not part of `values`, determined using `indexOf()`.
+Use `filter()` to remove values that are part of `values`, determined using `indexOf()`.
 
 ```js
 var difference = (arr, values) =>

snippets/object-from-key-value-pairs.md

@@ -0,0 +1,8 @@
+### Object from key-value pairs
+
+Use `map()` to create objects for each key-value pair, combine with `Object.assign()`.
+
+```js
+var objectFromPairs = arr =>
+  Object.assign(...arr.map( v => {return {[v[0]] : v[1]};} ));
+```

snippets/similarity-between-arrays.md

@@ -0,0 +1,8 @@
+### Similarity between arrays
+
+Use `filter()` to remove values that are not part of `values`, determined using `indexOf()`.
+
+```js
+var difference = (arr, values) =>
+  arr.filter(v => values.indexOf(v) !== -1);
+```