Arrays, Functions & Callbacks:
Here is a quick recap of some fundamental JavaScript concepts I revised today:
1.Array Length (.length):
mark.length gives the total size (number of elements) in an array.
2.Mixed Data Types in Arrays:
JavaScript arrays can store different types of data together:
const ar = [10, 20, 30, "abc", true];
3.The .filter() Method:
numbers.filter(display)
numbers ➔ Array name
display ➔ Function passed inside .filter()
4.Callback Functions:
A callback function is a function passed as an argument to another function.
Example: filterdemo(display)
5.Arrow Functions (=>):
A concise way to write functions in JavaScript.
