Tag, lint, build

README.md

@@ -12,6 +12,7 @@
 ### Array
 * [Array concatenation](#array-concatenation)
 * [Array difference](#array-difference)
+* [Array includes](#array-includes)
 * [Array intersection](#array-intersection)
 * [Array sample](#array-sample)
 * [Array union](#array-union)
@@ -142,6 +143,19 @@ const difference = (a, b) => { const s = new Set(b); return a.filter(x => !s.has
 
 [⬆ back to top](#table-of-contents)
 
+### Array includes
+
+Use `slice()` to offset the array/string and `indexOf()` to check if the value is included.
+Omit the last argument, `fromIndex`, to check the whole array/string.
+
+```js
+const includes = (collection, val, fromIndex=0) => collection.slice(fromIndex).indexOf(val) != -1;
+// includes("30-seconds-of-code", "code") -> true
+// includes([1, 2, 3, 4], [1, 2], 1) -> false
+```
+
+[⬆ back to top](#table-of-contents)
+
 ### Array intersection
 
 Create a `Set` from `b`, then use `Array.filter()` on `a` to only keep values contained in `b`.

snippets/array-includes.md

@@ -1,10 +1,10 @@
 ### Array includes
 
-Use `slice()` to offset the array/string. `Array.indexOf()` returns `-1` if the sub-string/array dosen't contain the given `value`.
+Use `slice()` to offset the array/string and `indexOf()` to check if the value is included.
+Omit the last argument, `fromIndex`, to check the whole array/string.
 
 ```js
 const includes = (collection, val, fromIndex=0) => collection.slice(fromIndex).indexOf(val) != -1;
-
 // includes("30-seconds-of-code", "code") -> true
 // includes([1, 2, 3, 4], [1, 2], 1) -> false
 ```

tag_database

@@ -1,6 +1,7 @@
 anagrams-of-string-(with-duplicates):string
 array-concatenation:array
 array-difference:array
+array-includes:array
 array-intersection:array
 array-sample:array
 array-union:array