Array Functions

JavaScript array functions are designed to help you manage strings by putting them into lists of similar items. These methods are built-in, meaning that the creation and manipulation of arrays are standardized in JavaScript for your convenience.
concat() :- Joins multiple arrays. Returns a new array.
copyWithin():- Copies elements from the array from one index to another.
every():- Checks if all the elements of an array pass a test.
fill():- Fills an array with some values.
filter():- Creates a new array using every element that passes a test.
find():- Creates a new array with all the elements that pass a test implemented by the provided function.
findIndex():- Returns the index of the first element which passes a test.
forEach():- Executes some code to each element of an array.
indexOf():- Returns the index of a specified element.
isArray():- Checks whether a specified element is in the array.
join():- Puts array elements into a string list.

Date Functions

The Date object is an inbuilt datatype of JavaScript language. It is used to work with dates and times. The Date object is created by using new keyword, i.e. new Date(). The Date object can be used date and time in terms of millisecond precision within 100 million days before or after 1/1/1970
Date():- It returns presents day’s date and time.
getDate():- It returns the day for the specified date.
getDay():- It returns the day of the week for the specified date.
getFullYear():- It returns the year of the specified date.
getYear():- This method returns the year in the specified date.
getHours():- It returns the hour in a specified date.
getMilliseconds():- It returns the milliseconds in the specified date.
getMinutes():- It returns the minutes in the specified date.
getMonth():- It returns the month in the specified date. This also find the month.
getSeconds():- This method returns the seconds in the specified date.
getTime():- This method returns the date in terms of numeric value as milliseconds.
setDate():- This method sets the day of the month for a specified date.
setFullYear():- This method sets the full year for a specified date.