The JavaScript cookbook contains lots of useful how-to articles that explain how to perform common things in JavaScript
Note: this is a living document. Over time this post will fill up with tons of useful how-tos
Strings
- How to uppercase the first letter of a string in JavaScript
- How to check if a string contains a substring in JavaScript
- How to replace all occurrences of a string in JavaScript
- How to convert a string to a number in JavaScript
- How to create a multiline string in JavaScript
- How to check if a string starts with another in JavaScript
Numbers
- How to trim the leading zero in a number in JavaScript
- How to format a number as a currency value in JavaScript
- How to generate a random number between two numbers in JavaScript
Dates
Objects
- How to remove a property from a JavaScript object
- How to inspect a JavaScript object
- How to deep clone a JavaScript object
- How to check if a JavaScript object property is undefined
- How to merge two objects in JavaScript
- How to access a method of an object dynamically in JavaScript
- How to use the destructuring syntax to work with arrays and objects in JavaScript
- How to count the number of properties in a JavaScript object
- How to list all methods of an object in JavaScript
Arrays
- How to remove an item from an Array in JavaScript
- How to append an item to an array in JavaScript
- How to initialize a new array with values in JavaScript
- How to use Async and Await with Array.map()
- How to empty a JavaScript array
- How to sort an array of objects by a property value in JavaScript
- How to get the unique properties of a set of objects in a JavaScript array