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30secondsofcode
2019-02-12 20:42:35 +00:00
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commit 6cd727c0e0
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7
README.md
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@ -668,13 +668,14 @@ const pipeAsyncFunctions = (...fns) => arg => fns.reduce((p, f) => p.then(f), Pr
<summary>Examples</summary>
```js
const sum = pipeAsyncFunctions(
x => x + 1,
x => new Promise(resolve => setTimeout(() => resolve(x + 2), 1000)),
x => x + 3,
async x => (await x) + 4
);
(async () => {
(async() => {
console.log(await sum(5)); // 15 (after one second)
})();
```
@ -2316,6 +2317,7 @@ Use `Array.prototype.filter()` to find array elements that return truthy values
The `func` is invoked with three arguments (`value, index, array`).
```js
const remove = (arr, func) =>
Array.isArray(arr)
? arr.filter(func).reduce((acc, val) => {
@ -5499,6 +5501,7 @@ Otherwise, return the product of `n` and the factorial of `n - 1`.
Throws an exception if `n` is a negative number.
```js
const factorial = n =>
n < 0
? (() => {
@ -6753,6 +6756,7 @@ Use `Object.keys(obj)` to iterate over the object's keys.
Use `Array.prototype.reduce()` to create a new object with the same values and mapped keys using `fn`.
```js
const deepMapKeys = (obj, f) =>
Array.isArray(obj)
? obj.map(val => deepMapKeys(val, f))
@ -6832,6 +6836,7 @@ Use the `in` operator to check if `target` exists in `obj`.
If found, return the value of `obj[target]`, otherwise use `Object.values(obj)` and `Array.prototype.reduce()` to recursively call `dig` on each nested object until the first matching key/value pair is found.
```js
const dig = (obj, target) =>
target in obj
? obj[target]

5
docs/adapter.html
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@ -127,13 +127,14 @@ Object<span class="token punctuation">.</span><span class="token function">assig
<span class="token keyword">const</span> fn <span class="token operator">=</span> <span class="token function">overArgs</span><span class="token punctuation">((</span>x<span class="token punctuation">,</span> y<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">[</span>x<span class="token punctuation">,</span> y<span class="token punctuation">], [</span>square<span class="token punctuation">,</span> double<span class="token punctuation">]);</span>
<span class="token function">fn</span><span class="token punctuation">(</span><span class="token number">9</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">);</span> <span class="token comment">// [81, 6]</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="pipeasyncfunctions">pipeAsyncFunctions</h4><p>Performs left-to-right function composition for asynchronous functions.</p><p>Use <code>Array.prototype.reduce()</code> with the spread operator (<code>...</code>) to perform left-to-right function composition using <code>Promise.then()</code>. The functions can return a combination of: simple values, <code>Promise</code>'s, or they can be defined as <code>async</code> ones returning through <code>await</code>. All functions must be unary.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">pipeAsyncFunctions</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token operator">...</span>fns<span class="token punctuation">)</span> <span class="token operator">=></span> arg <span class="token operator">=></span> fns<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>p<span class="token punctuation">,</span> f<span class="token punctuation">)</span> <span class="token operator">=></span> p<span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>f<span class="token punctuation">),</span> Promise<span class="token punctuation">.</span><span class="token function">resolve</span><span class="token punctuation">(</span>arg<span class="token punctuation">));</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token keyword">const</span> sum <span class="token operator">=</span> <span class="token function">pipeAsyncFunctions</span><span class="token punctuation">(</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js">
<span class="token keyword">const</span> sum <span class="token operator">=</span> <span class="token function">pipeAsyncFunctions</span><span class="token punctuation">(</span>
x <span class="token operator">=></span> x <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">,</span>
x <span class="token operator">=></span> <span class="token keyword">new</span> <span class="token class-name">Promise</span><span class="token punctuation">(</span>resolve <span class="token operator">=></span> <span class="token function">setTimeout</span><span class="token punctuation">(()</span> <span class="token operator">=></span> <span class="token function">resolve</span><span class="token punctuation">(</span>x <span class="token operator">+</span> <span class="token number">2</span><span class="token punctuation">),</span> <span class="token number">1000</span><span class="token punctuation">)),</span>
x <span class="token operator">=></span> x <span class="token operator">+</span> <span class="token number">3</span><span class="token punctuation">,</span>
<span class="token keyword">async</span> x <span class="token operator">=></span> <span class="token punctuation">(</span><span class="token keyword">await</span> x<span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token number">4</span>
<span class="token punctuation">);
(</span><span class="token keyword">async</span> <span class="token punctuation">()</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
(</span><span class="token keyword">async</span><span class="token punctuation">()</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token keyword">await</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">));</span> <span class="token comment">// 15 (after one second)</span>
<span class="token punctuation">})();</span>
</pre></div><div class="card code-card"><div class="section card-content"><h4><a href="https://frontendmasters.com/courses/es6-right-parts/" target="_blank" rel="noopener noreferrer">Recommended Resource - ES6: The Right Parts</a></h4><p>Learn new ES6 JavaScript language features like arrow function, destructuring, generators & more to write cleaner and more productive, readable programs.</p></div></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="pipefunctions">pipeFunctions</h4><p>Performs left-to-right function composition.</p><p>Use <code>Array.prototype.reduce()</code> with the spread operator (<code>...</code>) to perform left-to-right function composition. The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">pipeFunctions</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token operator">...</span>fns<span class="token punctuation">)</span> <span class="token operator">=></span> fns<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>f<span class="token punctuation">,</span> g<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token function">g</span><span class="token punctuation">(</span><span class="token function">f</span><span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">)));</span>

3
docs/index.html
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@ -407,7 +407,8 @@
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="reject">reject</h4><p>Takes a predicate and array, like <code>Array.prototype.filter()</code>, but only keeps <code>x</code> if <code>pred(x) === false</code>.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">reject</span> <span class="token operator">=</span> <span class="token punctuation">(</span>pred<span class="token punctuation">,</span> array<span class="token punctuation">)</span> <span class="token operator">=></span> array<span class="token punctuation">.</span><span class="token function">filter</span><span class="token punctuation">((</span><span class="token operator">...</span>args<span class="token punctuation">)</span> <span class="token operator">=> !</span><span class="token function">pred</span><span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">));</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token function">reject</span><span class="token punctuation">(</span>x <span class="token operator">=></span> x <span class="token operator">%</span> <span class="token number">2</span> <span class="token operator">===</span> <span class="token number">0</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 comment">// [1, 3, 5]</span>
<span class="token function">reject</span><span class="token punctuation">(</span>word <span class="token operator">=></span> word<span class="token punctuation">.</span>length <span class="token operator">></span> <span class="token number">4</span><span class="token punctuation">, [</span><span class="token string">'Apple'</span><span class="token punctuation">,</span> <span class="token string">'Pear'</span><span class="token punctuation">,</span> <span class="token string">'Kiwi'</span><span class="token punctuation">,</span> <span class="token string">'Banana'</span><span class="token punctuation">]);</span> <span class="token comment">// ['Pear', 'Kiwi']</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="remove">remove</h4><p>Removes elements from an array for which the given function returns <code>false</code>.</p><p>Use <code>Array.prototype.filter()</code> to find array elements that return truthy values and <code>Array.prototype.reduce()</code> to remove elements using <code>Array.prototype.splice()</code>. The <code>func</code> is invoked with three arguments (<code>value, index, array</code>).</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">remove</span> <span class="token operator">=</span> <span class="token punctuation">(</span>arr<span class="token punctuation">,</span> func<span class="token punctuation">)</span> <span class="token operator">=></span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="remove">remove</h4><p>Removes elements from an array for which the given function returns <code>false</code>.</p><p>Use <code>Array.prototype.filter()</code> to find array elements that return truthy values and <code>Array.prototype.reduce()</code> to remove elements using <code>Array.prototype.splice()</code>. The <code>func</code> is invoked with three arguments (<code>value, index, array</code>).</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js">
<span class="token keyword">const</span> <span class="token function-variable function">remove</span> <span class="token operator">=</span> <span class="token punctuation">(</span>arr<span class="token punctuation">,</span> func<span class="token punctuation">)</span> <span class="token operator">=></span>
Array<span class="token punctuation">.</span><span class="token function">isArray</span><span class="token punctuation">(</span>arr<span class="token punctuation">)</span>
<span class="token operator">?</span> arr<span class="token punctuation">.</span><span class="token function">filter</span><span class="token punctuation">(</span>func<span class="token punctuation">).</span><span class="token function">reduce</span><span class="token punctuation">((</span>acc<span class="token punctuation">,</span> val<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
arr<span class="token punctuation">.</span><span class="token function">splice</span><span class="token punctuation">(</span>arr<span class="token punctuation">.</span><span class="token function">indexOf</span><span class="token punctuation">(</span>val<span class="token punctuation">),</span> <span class="token number">1</span><span class="token punctuation">);</span>

3
docs/math.html
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@ -149,7 +149,8 @@ For teams, each rating can adjusted based on own team's average rating vs.
average rating of opposing team, with the score being added to their
own individual rating by supplying it as the third argument.
*/</span>
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="factorial">factorial</h4><p>Calculates the factorial of a number.</p><p>Use recursion. If <code>n</code> is less than or equal to <code>1</code>, return <code>1</code>. Otherwise, return the product of <code>n</code> and the factorial of <code>n - 1</code>. Throws an exception if <code>n</code> is a negative number.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">factorial</span> <span class="token operator">=</span> n <span class="token operator">=></span>
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="factorial">factorial</h4><p>Calculates the factorial of a number.</p><p>Use recursion. If <code>n</code> is less than or equal to <code>1</code>, return <code>1</code>. Otherwise, return the product of <code>n</code> and the factorial of <code>n - 1</code>. Throws an exception if <code>n</code> is a negative number.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js">
<span class="token keyword">const</span> <span class="token function-variable function">factorial</span> <span class="token operator">=</span> n <span class="token operator">=></span>
n <span class="token operator">&lt;</span> <span class="token number">0</span>
<span class="token operator">?</span> <span class="token punctuation">(()</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
<span class="token keyword">throw new</span> <span class="token class-name">TypeError</span><span class="token punctuation">(</span><span class="token string">'Negative numbers are not allowed!'</span><span class="token punctuation">);

6
docs/object.html
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@ -134,7 +134,8 @@
o<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token number">3</span><span class="token punctuation">;</span> <span class="token comment">// not allowed</span>
o<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">][</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token number">4</span><span class="token punctuation">;</span> <span class="token comment">// not allowed as well</span>
</pre></div><div class="card code-card"><div class="corner advanced"></div><div class="section card-content"><h4 id="deepmapkeys">deepMapKeys</h4><p>Deep maps an object keys.</p><p>Creates an object with the same values as the provided object and keys generated by running the provided function for each key.</p><p>Use <code>Object.keys(obj)</code> to iterate over the object's keys. Use <code>Array.prototype.reduce()</code> to create a new object with the same values and mapped keys using <code>fn</code>.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">deepMapKeys</span> <span class="token operator">=</span> <span class="token punctuation">(</span>obj<span class="token punctuation">,</span> f<span class="token punctuation">)</span> <span class="token operator">=></span>
</pre></div><div class="card code-card"><div class="corner advanced"></div><div class="section card-content"><h4 id="deepmapkeys">deepMapKeys</h4><p>Deep maps an object keys.</p><p>Creates an object with the same values as the provided object and keys generated by running the provided function for each key.</p><p>Use <code>Object.keys(obj)</code> to iterate over the object's keys. Use <code>Array.prototype.reduce()</code> to create a new object with the same values and mapped keys using <code>fn</code>.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js">
<span class="token keyword">const</span> <span class="token function-variable function">deepMapKeys</span> <span class="token operator">=</span> <span class="token punctuation">(</span>obj<span class="token punctuation">,</span> f<span class="token punctuation">)</span> <span class="token operator">=></span>
Array<span class="token punctuation">.</span><span class="token function">isArray</span><span class="token punctuation">(</span>obj<span class="token punctuation">)</span>
<span class="token operator">?</span> obj<span class="token punctuation">.</span><span class="token function">map</span><span class="token punctuation">(</span>val <span class="token operator">=></span> <span class="token function">deepMapKeys</span><span class="token punctuation">(</span>val<span class="token punctuation">,</span> f<span class="token punctuation">))
:</span> <span class="token keyword">typeof</span> obj <span class="token operator">===</span> <span class="token string">'object'</span>
@ -174,7 +175,8 @@ o<span class="token punctuation">[</span><span class="token number">1</span><spa
*/</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="defaults">defaults</h4><p>Assigns default values for all properties in an object that are <code>undefined</code>.</p><p>Use <code>Object.assign()</code> to create a new empty object and copy the original one to maintain key order, use <code>Array.prototype.reverse()</code> and the spread operator <code>...</code> to combine the default values from left to right, finally use <code>obj</code> again to overwrite properties that originally had a value.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">defaults</span> <span class="token operator">=</span> <span class="token punctuation">(</span>obj<span class="token punctuation">,</span> <span class="token operator">...</span>defs<span class="token punctuation">)</span> <span class="token operator">=></span> Object<span class="token punctuation">.</span><span class="token function">assign</span><span class="token punctuation">({},</span> obj<span class="token punctuation">,</span> <span class="token operator">...</span>defs<span class="token punctuation">.</span><span class="token function">reverse</span><span class="token punctuation">(),</span> obj<span class="token punctuation">);</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token function">defaults</span><span class="token punctuation">({</span> a<span class="token punctuation">:</span> <span class="token number">1</span> <span class="token punctuation">}, {</span> b<span class="token punctuation">:</span> <span class="token number">2</span> <span class="token punctuation">}, {</span> b<span class="token punctuation">:</span> <span class="token number">6</span> <span class="token punctuation">}, {</span> a<span class="token punctuation">:</span> <span class="token number">3</span> <span class="token punctuation">});</span> <span class="token comment">// { a: 1, b: 2 }</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="dig">dig</h4><p>Returns the target value in a nested JSON object, based on the given key.</p><p>Use the <code>in</code> operator to check if <code>target</code> exists in <code>obj</code>. If found, return the value of <code>obj[target]</code>, otherwise use <code>Object.values(obj)</code> and <code>Array.prototype.reduce()</code> to recursively call <code>dig</code> on each nested object until the first matching key/value pair is found.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">dig</span> <span class="token operator">=</span> <span class="token punctuation">(</span>obj<span class="token punctuation">,</span> target<span class="token punctuation">)</span> <span class="token operator">=></span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="dig">dig</h4><p>Returns the target value in a nested JSON object, based on the given key.</p><p>Use the <code>in</code> operator to check if <code>target</code> exists in <code>obj</code>. If found, return the value of <code>obj[target]</code>, otherwise use <code>Object.values(obj)</code> and <code>Array.prototype.reduce()</code> to recursively call <code>dig</code> on each nested object until the first matching key/value pair is found.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js">
<span class="token keyword">const</span> <span class="token function-variable function">dig</span> <span class="token operator">=</span> <span class="token punctuation">(</span>obj<span class="token punctuation">,</span> target<span class="token punctuation">)</span> <span class="token operator">=></span>
target <span class="token keyword">in</span> obj
<span class="token operator">?</span> obj<span class="token punctuation">[</span>target<span class="token punctuation">]
:</span> Object<span class="token punctuation">.</span><span class="token function">values</span><span class="token punctuation">(</span>obj<span class="token punctuation">).</span><span class="token function">reduce</span><span class="token punctuation">((</span>acc<span class="token punctuation">,</span> val<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span>

1
snippets/deepMapKeys.md
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@ -8,6 +8,7 @@ Use `Object.keys(obj)` to iterate over the object's keys.
Use `Array.prototype.reduce()` to create a new object with the same values and mapped keys using `fn`.
```js
const deepMapKeys = (obj, f) =>
Array.isArray(obj)
? obj.map(val => deepMapKeys(val, f))

1
snippets/dig.md
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@ -6,6 +6,7 @@ Use the `in` operator to check if `target` exists in `obj`.
If found, return the value of `obj[target]`, otherwise use `Object.values(obj)` and `Array.prototype.reduce()` to recursively call `dig` on each nested object until the first matching key/value pair is found.
```js
const dig = (obj, target) =>
target in obj
? obj[target]

1
snippets/factorial.md
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@ -8,6 +8,7 @@ Otherwise, return the product of `n` and the factorial of `n - 1`.
Throws an exception if `n` is a negative number.
```js
const factorial = n =>
n < 0
? (() => {

3
snippets/pipeAsyncFunctions.md
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@ -11,13 +11,14 @@ const pipeAsyncFunctions = (...fns) => arg => fns.reduce((p, f) => p.then(f), Pr
```
```js
const sum = pipeAsyncFunctions(
x => x + 1,
x => new Promise(resolve => setTimeout(() => resolve(x + 2), 1000)),
x => x + 3,
async x => (await x) + 4
);
(async () => {
(async() => {
console.log(await sum(5)); // 15 (after one second)
})();
```

1
snippets/remove.md
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@ -6,6 +6,7 @@ Use `Array.prototype.filter()` to find array elements that return truthy values
The `func` is invoked with three arguments (`value, index, array`).
```js
const remove = (arr, func) =>
Array.isArray(arr)
? arr.filter(func).reduce((acc, val) => {

4
test/_30s.js
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@ -235,6 +235,7 @@ const deepFreeze = obj =>
prop =>
!(obj[prop] instanceof Object) || Object.isFrozen(obj[prop]) ? null : deepFreeze(obj[prop])
) || Object.freeze(obj);
const deepMapKeys = (obj, f) =>
Array.isArray(obj)
? obj.map(val => deepMapKeys(val, f))
@ -263,6 +264,7 @@ const differenceBy = (a, b, fn) => {
return a.filter(x => !s.has(fn(x)));
};
const differenceWith = (arr, val, comp) => arr.filter(a => val.findIndex(b => comp(a, b)) === -1);
const dig = (obj, target) =>
target in obj
? obj[target]
@ -338,6 +340,7 @@ const extendHex = shortHex =>
.split('')
.map(x => x + x)
.join('');
const factorial = n =>
n < 0
? (() => {
@ -985,6 +988,7 @@ const reducedFilter = (data, keys, fn) =>
}, {})
);
const reject = (pred, array) => array.filter((...args) => !pred(...args));
const remove = (arr, func) =>
Array.isArray(arr)
? arr.filter(func).reduce((acc, val) => {