Travis build: 1168

README.md

@@ -768,12 +768,18 @@ filterNonUnique([1, 2, 2, 3, 4, 4, 5]); // [1,3,5]
 
 ### flatten
 
-Flattens an array.
+Flattens an array up to the specified depth.
 
-Use a new array, `Array.concat()` and the spread operator (`...`) to cause a shallow denesting of any contained arrays.
+Use recursion, decrementing `depth` by 1 for each level of depth.
+Use `Array.reduce()` and `Array.concat()` to merge elements or arrays.
+Base case, for `depth` equal to `1` stops recursion.
+Omit the second argument, `depth` to flatten only to a depth of `1` (single flatten).
 
 ```js
-const flatten = arr => [].concat(...arr);
+const flatten = (arr, depth = 1) =>
+  depth != 1
+    ? arr.reduce((a, v) => a.concat(Array.isArray(v) ? flatten(v, depth - 1) : v), [])
+    : arr.reduce((a, v) => a.concat(v), []);
 ```
 
 <details>
@@ -781,6 +787,7 @@ const flatten = arr => [].concat(...arr);
 
 ```js
 flatten([1, [2], 3, 4]); // [1, 2, 3, 4]
+flatten([1, [2, [3, [4, 5], 6], 7], 8], 2); // [1, 2, 3, [4, 5], 6, 7, 8]
 ```
 
 </details>
@@ -5201,6 +5208,7 @@ const httpPost = (url, callback, data = null, err = console.error) => {
 
 
 
+
 const newPost = {
   "userId": 1,
   "id": 1337,

docs/index.html

@@ -119,8 +119,12 @@ Object<span class="token punctuation">.</span><span class="token function">assig
 </pre><label class="collapse">Show examples</label><pre class="language-js"><span class="token function">everyNth</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">,</span> <span class="token number">6</span><span class="token punctuation">],</span> <span class="token number">2</span><span class="token punctuation">);</span> <span class="token comment">// [ 2, 4, 6 ]</span>
 </pre><button class="primary clipboard-copy">&#128203;&nbsp;Copy to clipboard</button></div></div><div class="card fluid"><h3 id="filternonunique" class="section double-padded">filterNonUnique</h3><div class="section double-padded"><p>Filters out the non-unique values in an array.</p><p>Use <code>Array.filter()</code> for an array containing only the unique values.</p><pre class="language-js"><span class="token keyword">const</span> <span class="token function-variable function">filterNonUnique</span> <span class="token operator">=</span> arr <span class="token operator">=></span> arr<span class="token punctuation">.</span><span class="token function">filter</span><span class="token punctuation">(</span>i <span class="token operator">=></span> arr<span class="token punctuation">.</span><span class="token function">indexOf</span><span class="token punctuation">(</span>i<span class="token punctuation">)</span> <span class="token operator">===</span> arr<span class="token punctuation">.</span><span class="token function">lastIndexOf</span><span class="token punctuation">(</span>i<span class="token punctuation">));</span>
 </pre><label class="collapse">Show examples</label><pre class="language-js"><span class="token function">filterNonUnique</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">]);</span> <span class="token comment">// [1,3,5]</span>
-</pre><button class="primary clipboard-copy">&#128203;&nbsp;Copy to clipboard</button></div></div><div class="card fluid"><h3 id="flatten" class="section double-padded">flatten</h3><div class="section double-padded"><p>Flattens an array.</p><p>Use a new array, <code>Array.concat()</code> and the spread operator (<code>...</code>) to cause a shallow denesting of any contained arrays.</p><pre class="language-js"><span class="token keyword">const</span> <span class="token function-variable function">flatten</span> <span class="token operator">=</span> arr <span class="token operator">=></span> <span class="token punctuation">[].</span><span class="token function">concat</span><span class="token punctuation">(</span><span class="token operator">...</span>arr<span class="token punctuation">);</span>
+</pre><button class="primary clipboard-copy">&#128203;&nbsp;Copy to clipboard</button></div></div><div class="card fluid"><h3 id="flatten" class="section double-padded">flatten</h3><div class="section double-padded"><p>Flattens an array up to the specified depth.</p><p>Use recursion, decrementing <code>depth</code> by 1 for each level of depth. Use <code>Array.reduce()</code> and <code>Array.concat()</code> to merge elements or arrays. Base case, for <code>depth</code> equal to <code>1</code> stops recursion. Omit the second argument, <code>depth</code> to flatten only to a depth of <code>1</code> (single flatten).</p><pre class="language-js"><span class="token keyword">const</span> <span class="token function-variable function">flatten</span> <span class="token operator">=</span> <span class="token punctuation">(</span>arr<span class="token punctuation">,</span> depth <span class="token operator">=</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token operator">=></span>
+  depth <span class="token operator">!=</span> <span class="token number">1</span>
+    <span class="token operator">?</span> arr<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>a<span class="token punctuation">,</span> v<span class="token punctuation">)</span> <span class="token operator">=></span> a<span class="token punctuation">.</span><span class="token function">concat</span><span class="token punctuation">(</span>Array<span class="token punctuation">.</span><span class="token function">isArray</span><span class="token punctuation">(</span>v<span class="token punctuation">)</span> <span class="token operator">?</span> <span class="token function">flatten</span><span class="token punctuation">(</span>v<span class="token punctuation">,</span> depth <span class="token operator">-</span> <span class="token number">1</span><span class="token punctuation">) :</span> v<span class="token punctuation">), [])
+    :</span> arr<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>a<span class="token punctuation">,</span> v<span class="token punctuation">)</span> <span class="token operator">=></span> a<span class="token punctuation">.</span><span class="token function">concat</span><span class="token punctuation">(</span>v<span class="token punctuation">), []);</span>
 </pre><label class="collapse">Show examples</label><pre class="language-js"><span class="token function">flatten</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">, [</span><span class="token number">2</span><span class="token punctuation">],</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">]);</span> <span class="token comment">// [1, 2, 3, 4]</span>
+<span class="token function">flatten</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">, [</span><span class="token number">2</span><span class="token punctuation">, [</span><span class="token number">3</span><span class="token punctuation">, [</span><span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">],</span> <span class="token number">6</span><span class="token punctuation">],</span> <span class="token number">7</span><span class="token punctuation">],</span> <span class="token number">8</span><span class="token punctuation">],</span> <span class="token number">2</span><span class="token punctuation">);</span> <span class="token comment">// [1, 2, 3, [4, 5], 6, 7, 8]</span>
 </pre><button class="primary clipboard-copy">&#128203;&nbsp;Copy to clipboard</button></div></div><div class="card fluid"><h3 id="flattendepth" class="section double-padded">flattenDepth</h3><div class="section double-padded"><p>Flattens an array up to the specified depth.</p><p>Use recursion, decrementing <code>depth</code> by 1 for each level of depth. Use <code>Array.reduce()</code> and <code>Array.concat()</code> to merge elements or arrays. Base case, for <code>depth</code> equal to <code>1</code> stops recursion. Omit the second element, <code>depth</code> to flatten only to a depth of <code>1</code> (single flatten).</p><pre class="language-js"><span class="token keyword">const</span> <span class="token function-variable function">flattenDepth</span> <span class="token operator">=</span> <span class="token punctuation">(</span>arr<span class="token punctuation">,</span> depth <span class="token operator">=</span> <span class="token number">1</span><span class="token punctuation">)</span> <span class="token operator">=></span>
   depth <span class="token operator">!=</span> <span class="token number">1</span>
     <span class="token operator">?</span> arr<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>a<span class="token punctuation">,</span> v<span class="token punctuation">)</span> <span class="token operator">=></span> a<span class="token punctuation">.</span><span class="token function">concat</span><span class="token punctuation">(</span>Array<span class="token punctuation">.</span><span class="token function">isArray</span><span class="token punctuation">(</span>v<span class="token punctuation">)</span> <span class="token operator">?</span> <span class="token function">flattenDepth</span><span class="token punctuation">(</span>v<span class="token punctuation">,</span> depth <span class="token operator">-</span> <span class="token number">1</span><span class="token punctuation">) :</span> v<span class="token punctuation">), [])
@@ -1163,6 +1167,7 @@ Logs: {
 </pre><label class="collapse">Show examples</label><pre class="language-js">
 
 
+
 <span class="token keyword">const</span> newPost <span class="token operator">=</span> <span class="token punctuation">{</span>
   <span class="token string">"userId"</span><span class="token punctuation">:</span> <span class="token number">1</span><span class="token punctuation">,</span>
   <span class="token string">"id"</span><span class="token punctuation">:</span> <span class="token number">1337</span><span class="token punctuation">,</span>

snippets/httpPost.md

@@ -24,6 +24,7 @@ const httpPost = (url, callback, data = null, err = console.error) => {
 
 
 
+
 const newPost = {
   "userId": 1,
   "id": 1337,