JAVA SCRIPT ARRAY METHODS

JavaScript Basics: Arrays, Functions & Callbacks
​Here is a quick recap of some fundamental JavaScript concepts I revised today:
​ Array Length (.length)
​mark.length gives the total size (number of elements) in an array.

​Mixed Data Types in Arrays
​JavaScript arrays can store different types of data together:
const ar = [10, 20, 30, "abc", true];

​ The .filter() Method
​numbers.filter(display)

​numbers ➔ Array name

​display ➔ Function passed inside .filter()

​Callback Functions
​A callback function is a function passed as an argument to another function.

​Example: filterdemo(display)

​Arrow Functions (=>)
​A concise way to write functions in JavaScript.