This commit is contained in:
Stefan Feješ
2017-12-19 21:46:36 +01:00
parent 6c9459fcf1
commit 3dcf5d687e
2 changed files with 13 additions and 13 deletions

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@ -408,7 +408,7 @@ Use `Array((end + 1) - start)` to create an array of the desired length, `Array.
You can omit `start` to use a default value of `0`.
```js
const initializeArrayWithRange = (end, start = 0) =>
const initializeArrayWithRange = (end, start = 0) =>
Array.from({ length: (end + 1) - start }).map((v, i) => i + start);
// initializeArrayWithRange(5) -> [0,1,2,3,4,5]
// initializeArrayWithRange(7, 3) -> [3,4,5,6,7]
@ -463,7 +463,7 @@ Maps the values of an array to an object using a function, where the key-value p
Use an anonymous inner function scope to declare an undefined memory space, using closures to store a return value. Use a new `Array` to stor the array with a map of the function over its data set and a comma operator to return a second step, without needing to move from one context to another (due to closures and order of operations).
```js
const mapObject = (arr, fn) =>
const mapObject = (arr, fn) =>
(a => (a = [arr, arr.map(fn)], a[0].reduce( (acc,val,ind) => (acc[val] = a[1][ind], acc), {}) )) ( );
/*
const squareIt = arr => mapObject(arr, a => a*a)
@ -535,14 +535,14 @@ Mutates the original array to filter out the values at the specified indexes.
Use `Array.filter()` and `Array.includes()` to pull out the values that are not needed.
Use `Array.length = 0` to mutate the passed in array by resetting it's length to zero and `Array.push()` to re-populate it with only the pulled values.
Use `Array.push()` to keep track of pulled values
Use `Array.push()` to keep track of pulled values
```js
const pullAtIndex = (arr, pullArr) => {
let removed = [];
let pulled = arr.map((v, i) => pullArr.includes(i) ? removed.push(v) : v)
.filter((v, i) => !pullArr.includes(i))
arr.length = 0;
arr.length = 0;
pulled.forEach(v => arr.push(v));
return removed;
}
@ -562,11 +562,11 @@ Mutates the original array to filter out the values specified. Returns the remov
Use `Array.filter()` and `Array.includes()` to pull out the values that are not needed.
Use `Array.length = 0` to mutate the passed in array by resetting it's length to zero and `Array.push()` to re-populate it with only the pulled values.
Use `Array.push()` to keep track of pulled values
Use `Array.push()` to keep track of pulled values
```js
const pullAtValue = (arr, pullArr) => {
let removed = [],
let removed = [],
pushToRemove = arr.forEach((v, i) => pullArr.includes(v) ? removed.push(v) : v),
mutateTo = arr.filter((v, i) => !pullArr.includes(v));
arr.length = 0;
@ -1219,7 +1219,7 @@ const isEven = num => num % 2 === 0;
### isPrime
Checks if the provided intiger is primer number.
Checks if the provided intiger is prime number.
Returns `false` if the provided number has positive divisors other than 1 and itself or if the number itself is less than 2.
@ -1527,7 +1527,7 @@ a === b -> false
Checks if the predicate (second argument) is truthy on all elements of a collection (first argument).
Use `Array.every()` to check if each passed object has the specified property and if it returns a truthy value.
```js
truthCheckCollection = (collection, pre) => (collection.every(obj => obj[pre]));
// truthCheckCollection([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}], "sex") -> true

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@ -302,7 +302,7 @@ Use <code>Array.reduce()</code> to create an object, where the keys are produced
<p>Initializes an array containing the numbers in the specified range where <code>start</code> and <code>end</code> are inclusive.</p>
<p>Use <code>Array((end + 1) - start)</code> to create an array of the desired length, <code>Array.map()</code> to fill with the desired values in a range.
You can omit <code>start</code> to use a default value of <code>0</code>.</p>
<pre><code class="language-js">const initializeArrayWithRange = (end, start = 0) =&gt;
<pre><code class="language-js">const initializeArrayWithRange = (end, start = 0) =&gt;
Array.from({ length: (end + 1) - start }).map((v, i) =&gt; i + start);
// initializeArrayWithRange(5) -&gt; [0,1,2,3,4,5]
// initializeArrayWithRange(7, 3) -&gt; [3,4,5,6,7]
@ -329,7 +329,7 @@ You can omit <code>value</code> to use a default value of <code>0</code>.</p>
</div></div><br/><div class="card fluid"><div class="section double-padded"><h3 id="mapobject">mapObject</h3></div><div class="section double-padded">
<p>Maps the values of an array to an object using a function, where the key-value pairs consist of the original value as the key and the mapped value.</p>
<p>Use an anonymous inner function scope to declare an undefined memory space, using closures to store a return value. Use a new <code>Array</code> to stor the array with a map of the function over its data set and a comma operator to return a second step, without needing to move from one context to another (due to closures and order of operations).</p>
<pre><code class="language-js">const mapObject = (arr, fn) =&gt;
<pre><code class="language-js">const mapObject = (arr, fn) =&gt;
(a =&gt; (a = [arr, arr.map(fn)], a[0].reduce( (acc,val,ind) =&gt; (acc[val] = a[1][ind], acc), {}) )) ( );
/*
const squareIt = arr =&gt; mapObject(arr, a =&gt; a*a)
@ -379,7 +379,7 @@ Use <code>Array.push()</code> to keep track of pulled values</p>
let removed = [];
let pulled = arr.map((v, i) =&gt; pullArr.includes(i) ? removed.push(v) : v)
.filter((v, i) =&gt; !pullArr.includes(i))
arr.length = 0;
arr.length = 0;
pulled.forEach(v =&gt; arr.push(v));
return removed;
}
@ -396,7 +396,7 @@ Use <code>Array.push()</code> to keep track of pulled values</p>
Use <code>Array.length = 0</code> to mutate the passed in array by resetting it's length to zero and <code>Array.push()</code> to re-populate it with only the pulled values.
Use <code>Array.push()</code> to keep track of pulled values</p>
<pre><code class="language-js">const pullAtValue = (arr, pullArr) =&gt; {
let removed = [],
let removed = [],
pushToRemove = arr.forEach((v, i) =&gt; pullArr.includes(v) ? removed.push(v) : v),
mutateTo = arr.filter((v, i) =&gt; !pullArr.includes(v));
arr.length = 0;
@ -763,7 +763,7 @@ Returns <code>true</code> if the number is even, <code>false</code> if the numbe
// isEven(3) -&gt; false
</code></pre>
</div></div><br/><div class="card fluid"><div class="section double-padded"><h3 id="isprime">isPrime</h3></div><div class="section double-padded">
<p>Checks if the provided intiger is primer number.</p>
<p>Checks if the provided intiger is prime number.</p>
<p>Returns <code>false</code> if the provided number has positive divisors other than 1 and itself or if the number itself is less than 2.</p>
<pre><code class="language-js">const isPrime = num =&gt;
for (var i = 2; i &lt; num; i++) if (num % i == 0) return false;