A brief overview depends on today’s topics

1.Data type:

There are two types of data in JS language. One is primitive and another is non-primitive. Number and strings are primitive data. Whereas objects and functions are non-primitive data. The primitive data stays in the distance but useable whenever needs. The non-primitive data is always in code to get results like functions and objects.


Javascript is also used to give a question’s answer in its way. That is called expression. For example — console.log(5+5). To know which types of data this is, typeof operator is being used.

3.Coding style:

One of the most important features of a good programmer is his/her coding style. It should have to be clean and organized. A space between parameters, curly brace on the same line after space, A semicolon is mandatory these are the good practice for a good coder.


Commenting is also a good practice for a programmer. Sometimes beginner misuses it. A coder can comment inside a function if he/she needs it. Comments help others to understand your coding properly.


Chaing is the process of how a device collects data from various places then provides data on what users are searching for. It gives obstacles to create the same data again and again in storage. Users can get an early response from this system. It has some problems also.

6.Cross-browser testing:

Cross-browser is a system to check your website which you created as a web developer is working properly in any devices or in an browsers. One of the most important responsibilities is to ensure his/her website is okay from several devices and browser. By checking this test user can get a proper website to use.

7.Arrow function:

In Es6 arrow function is new version of function . It makes function easier to write . It has some limitations .

const numbers = [2,3,4,5, 14, 18, 20]

console.log(numbers.map(number => number > 10))

//expected output 14, 18, 20;

8.Spread operator:

Spread operator helps to bring array or string data and expose it for create something .

function sum(a,b,c) {
return a+b+c;

const numbers = [5, 2, 6];

// expected output: 13

9.Default function parameter:

Defaut parameter gives this chance to keep value when parameters calls and use when its value doesn’t call.

function multiply(a, b = 1) {
return a * b;

console.log(multiply(5, 2));
// expected output: 10

// expected output: 5

10.Emerging Best Practices for Block Bindings:

In Es6 variable has converted into two new name depends on its use. If variable can change let can be use . If variable doesn’t change const can be use as variable name.