# One-lines

* ### How to Capitalize Text <a href="#id-1-how-to-capitalize-text" id="id-1-how-to-capitalize-text"></a>

  ```js
  const capitalize = (str) => `${str.charAt(0).toUpperCase()}${str.slice(1)}`;
  ```

* ### How to Calculate Percent <a href="#id-2-how-to-calculate-percent" id="id-2-how-to-calculate-percent"></a>

  ```js
  const calculatePercent = (value, total) => Math.round((value / total) * 100)
  ```

* ### How to Get a Random Element <a href="#id-3-how-to-get-a-random-element" id="id-3-how-to-get-a-random-element"></a>

  ```js
  const getRandomItem = (items) =>  items[Math.floor(Math.random() * items.length)];
  ```

* ### How to Remove Duplicate Elements <a href="#id-4-how-to-remove-duplicate-elements" id="id-4-how-to-remove-duplicate-elements"></a>

  ```js
  const removeDuplicates = (arr) => [...new Set(arr)];
  ```

* ### How to Sort Elements By Certain Property <a href="#id-5-how-to-sort-elements-by-certain-property" id="id-5-how-to-sort-elements-by-certain-property"></a>

  ```js
  const sortBy = (arr, key) => arr.sort((a, b) => a[key] > b[key] ? 1 : a[key] < b[key] ? -1 : 0);
  ```

* ### How to Check if Arrays/Objects are Equal <a href="#id-6-how-to-check-if-arrays-objects-are-equal" id="id-6-how-to-check-if-arrays-objects-are-equal"></a>

  ```js
  const isEqual = (a, b) => JSON.stringify(a) === JSON.stringify(b);
  ```

* ### How to Count Number of Occurrences <a href="#id-7-how-to-count-number-of-occurrences" id="id-7-how-to-count-number-of-occurrences"></a>

  ```js
  const countOccurrences = (arr, value) => arr.reduce((a, v) => (v === value ? a + 1 : a), 0);
  ```

* ### How to Wait for a Certain Amount of Time <a href="#id-8-how-to-wait-for-a-certain-amount-of-time" id="id-8-how-to-wait-for-a-certain-amount-of-time"></a>

  ```js
  const wait = async (milliseconds) => new Promise((resolve) => setTimeout(resolve, milliseconds));
  ```

* ### How to Use the Pluck Property from Array of Objects <a href="#id-9-how-to-use-the-pluck-property-from-array-of-objects" id="id-9-how-to-use-the-pluck-property-from-array-of-objects"></a>

  ```js
  const pluck = (objs, key) => objs.map((obj) => obj[key]);
  ```

* ### How to Insert an Element at a Certain Position <a href="#id-10-how-to-insert-an-element-at-a-certain-position" id="id-10-how-to-insert-an-element-at-a-certain-position"></a>

  ```js
  const insert = (arr, index, newItem) => [...arr.slice(0, index), newItem, ...arr.slice(index)];
  ```

***

> Reference

<https://www.freecodecamp.org/news/javascript-one-liners-to-use-in-every-project/>


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