Difference between var, let & const

By using var old way of defining variables. But javascript still maintains this type of syntax so, that old written code can also be executed and run by language because after an update each code updates a crucial thing.

var p_name = "jhon";
console.log(p_name); // will print jhon
p_name = "Rahul";
console.log(p_name); // will print Rahul
var p_name="Ramesh";
console.log(p_name);

In the above code, you can see it different way of defining var. The var is globally scoped so, you can define its top, and can be modified anywhere wherever required let me explain by example.

var username = "Jhon";
var age = 24;
if (age > 23) {
    var usename = "Mosh"; 
}
console.log(usename) // Will print "Mosh"

In the above example, you can see that we have defined a username and in the if statement block is modified and can be accessed outside the block and able to print it. But in the case of let and const this will not happen because both are block scoped so, will able to access within the block the same thing let me explain to you by example.

let username = "Jhon";
let age = 24;
if (age > 23) {
     let usename = "Mosh"; 
}
console.log(usename) // Will print usename is not defined

If we print the username then will throw an error because we again define in if block and it is block-scoped and their scope ends there if we do not again initialize with let in if block then will not throw an error. You can initialize a single time and can modify the value anywhere.

The const works the same as the variable but the main difference is that their value can not be modified within the block or outside the block in this datatype you can add value a single time and will same throughout the execution.

const fullname = "Rakesh Kumar";
console.log(fullname); // Will print Rakesh Kumar
fullname = "Mahesh"; // TypeError: Assignment to constant variable.

Arrow function in JavaScript ES6

It’s the same as a normal function that we create we create as usual like below let’s take an example of the addition of two numbers this function will add two provided numbers and return it.

function add(n1, n2){
	return n1+n2;
}
console.log(add(5,2)); // Will print 7

In JavaScript, an arrow function is a shortcut for writing functions. Compared to a conventional function expression, it is syntactically more compact and has several specific features, particularly with regard to this binding. This can be written by using => (“fat arrow”) syntax same function converts into an arrow function. There is also no difference in calling.

const add = (a, b) => {
  return  a + b;
};
console.log(add(5,2)); // Will print 7

For more convenience, we can also remove “{}” from the function definition. But there is a different calling for single and multiple parameters let see the example for both and single and multiple parameters.

const add = (a, b) => a + b;
console.log(add(5,2)); // Will print 7

const doubler = x => 2 * x;
console.log(doubler(5)); // Will print 10

const say = () => 'Say Hello';
console.log(say()); // Will Say Hello

use case for arrow function:
This implementation in short inline actions, like array operations (map, filter, reduce)

Differences from Regular Functions:

Lexical this Binding: Arrow functions don’t have a context of their own. Rather, they inherit this from the global scope or surrounding function. When you wish to maintain the surrounding scope’s value during callbacks, this is quite helpful.

function counter() {
  this.increment = 0;
  setInterval(() => {
    this.increment++; // 'this' refers to the counter instance
  }, 1000);
}
let c = new counter();
console.log(c.age); // will print 0

In the above example, you can see it will print 0 because of this reference to global scope. If we
console.log(this.increment)
within the setInterval curly braces inside then will print. So, it’s globally scoped and block context.

Cannot be used as Constructors:
The arrow function can not be used as a constructor you can see in the above example like
let c = new counter();
But if we can try with same thing with the arrow function will print the below error.
TypeError: counter is not a constructor

Implicit return:
When creating a single argument function then return the keyword not required by default omitted.
const doubler = x => 2 * x;
In this example, you can see I have not used the return keyword.

Use Cases of arrow function in JavaScript ES6

The best implementation of the arrow function you can see in map, filter, and reduce.

Modules in JavaScript ES6

JavaScript modules were established through the ES6 module syntax, providing a standardized approach for importing and exporting code across different files. This modularity enables programmers to organize their code more effectively and facilitates the sharing of functionality among various components of an application.

To explain the module let’s take an example that already stated that modular means we can write code in different files and use any place so let me create three files.
user.js // contain user information
address.js //will contain details related to address
main.js // it's the final file in which call both above file code

Exporting from a Module

Default Export:

Now I have created first file user.js in which you can see it I have saved the user information in variable user and at the end I have added the line export default user; this code provides the ability to use method, variable, etc in another file. In default export, we can export only the single class, method, and variable in another file by import.

// Filename : user.js 
//---------------------------
const user = {
    username:"Jhon",
    email:"john@gmail.com"
}
export default user;

Named Exports:

Now move to 2nd file address.js in which handles user address-related information. Also will see the syntax for named export. To define named export we have to write export preceding to function, variable or class so that can be exported and used in another place. Help of named export we can export multiple function variables and classes.

// Filename : address.js 
//---------------------------
export let getCity = () =>{
    return "Noida";
}
export let addressId = 25;

Importing from a Module in JavaScript ES6

Note:
For importing modules in html file need to add a type module then the module feature will work and the file call should be from a sever like localhost or any server extensions that are available that can be used like Live server which is compatible with Visual Studio Code if you are using Visual Studio Code.

So, now we add the main file main.js their code explains further. This file will add the main execution and will use the code that is written in the file user.js and address.js. So, In the HTML file need to add a statement like below

<script type="module" src="main.js" ></script>

Named Imports:

you can see below code there is added statement
import {getCity, addressId} address from './address.js';
In which getCity, addressId are the function and variable and ./address.js path of the file in which function and variable are defined.

// Filename : main.js 
//---------------------------
import {getCity, addressId} address  from './address.js'; 
console.log(getCity()); // will print Noida
console.log(addressId); // will print  25

Renaming Imports:

For code readability or any purpose if need to rename the name of a function, variable, or class name then in the module feature you can do it same thing explored by below code.

import {addressId as id}  from './address.js';
console.log(id) //will print 25

Above code, you can see addressId changed as id and print the same.

Import All:

In the module import, you can import all function methods and variables in a single variable an object by using using * as so, that no need to import separately same thing explain by code.

import * as address  from './address.js';
console.log(address.getCity()); // Will print Noida
console.log(address.addressId); // will print id 25

Default import

Now let me show how can import the default exported module more and less it works like importing all but there is no need to write * as .

import user  from './user.js';
console.log(user.username); // will print Jhon

You can also rename in default import.

import u  from './user.js';
console.log(u.username); // will print Jhon

Benefits of Using Modules

• Encapsulation: Modules make code isolated, you can maintain a global namespace more freely by making block-scoped or module-based code.
• Reusability: The same method and variable can be used anywhere there is no need to define and write code again and again.
• Maintainability: Code becomes more organized and readable so that team members or code reviewers can easily understand the code and easy to maintain future.

class & object / oops concept in javascript es6

It is used in approximately all programming languages like PHP, Python, Java, and Javascript. Class-based code has many features like code reusability, readability also helps in memory optimization. It’s a blueprint for creating objects. This feature of javascript es6 is used by many popular frameworks like React, angular, and nextJs. Class code structure definition and calling are the same in all languages only syntax differences are there. Please check the below example for class.

class userDetail{
	// Default constructor
	constructor(n){
		this.name = n;
		this.source = "Default";
	}
	// Individual variable
	user_id = 10;
	// Arrow function
	address = () => {
		return {city:"Noida",state:"UP",country:"India"};
	}
}
let user = new userDetail("Jhon"); // Set default name by constructor
console.log(user.user_id); // Will print 10
console.log(user.name); // will print Jhon
console.log(user.address().city); // Will print Noida

We have defined a constructor which calls when the class is initialized and we can assign variable value. We can do all things in class that we can do in global space like define arrow function and define normal variables.

Class Inheritance in javascript es6

The code that is already defined or written needs to be reused in the context of inheritance. For example in the class userDetail the written method and variable need to be used and write the next code then it’s possible by Inheritance. The code extended by keyword extends then adds the class name like extends userDetail

class cart extends userDetail{

	getProducts(){
		return ["Apple Mobile","Boat Headphone","Mobile Charger"];
	}
}
let user = new cart("Jhon"); // Set default name by constructor
console.log(user.user_id);   // Will print 10
console.log(user.name); // will print Jhon
console.log(user.getProducts()[0]); // will print Apple Mobile

The variable user_id and name is not defined in the class cart but still print name and user_id because the code of existing class userDetail added or Inherited in class cart

Array and object Destructuring in in javascript es6

Assigning values from array or object to a variable or you can say unpack values from an array and assign them to variables.

const colors = ['red', 'green', 'blue'];
const [first, second, third] = colors;

console.log(first);  // Output: 'red'
console.log(second); // Output: 'green'
console.log(third);  // Output: 'blue'

In this, if want skip any variable you can do it by skipping assigned variable like below.

const colors = ['red', 'green', 'blue'];
const [first, second] = colors;
console.log(first);  // Output: 'red'
console.log(second); // Output: 'green'

Object Destructuring

You can assign properties to variables by unpacking them from an object utilizing object destructuring. Unless you provide an alternative name, the variable names must correspond to the property names.

const person = { name: 'Alice', age: 25, city: 'New York' };
const { name, age, city } = person;
console.log(name); // Output: 'Alice'
console.log(age);  // Output: 25

// You can rename variable in object destructuring 

const person = { name: 'Alice', age: 25 };
const { name: personName, age: personAge } = person;
console.log(personName); // Output: 'Alice'
console.log(personAge);  // Output: 25

spread and rest operator in javascript es6

Both operators are represented by three dots ... with the help of these, we can collect the data and spread the next place and also provide flexibility to collect data for function.

Spread Operator

This operator spreads the value of the addition of value to the next variable it works with both array and object. Let’s understand by code.

let carBrand = ["Audi","Ferrai","Hudai"];
let autoBrand = [...carBrand, "Tata", "Nissan"];
console.log(autoBrand); // will print [ 'Audi', 'Ferrai', 'Hudai', 'Tata', 'Nissan' ]

let postAutoBrand = ["Tata", "Nissan", ...carBrand];
console.log(postAutoBrand); // will print [ 'Tata', 'Nissan', 'Audi', 'Ferrai', 'Hudai' ]

In the above code, we have defined three brands in variable carBrand. Now these three values spread in variable autoBrand by using … and with the use of spread, you can add values at the start and end of indexing.

Rest operator

It also works the same as the rest operator spread operator works for copy values but the rest operator works for the collection of multiple values or data.
Use Case :
Suppose a function needs to pass a dynamic parameter like below.

function userList(user1, user2, user3){
    return [user1,user2, user3];
}
console.log(userList("Jhon", "Ram", "Nick")); // [ 'Jhon', 'Ram', 'Nick' ]
console.log(userList("Jhon")); // [ 'Jhon', undefined, undefined ]

You can see that when we did not pass all three parameters in the second call. Then it added undefined on places 2nd and 3rd. So, to fix this issue we have to use the rest operator which collects values in an array format

function userList(...users){
    return users;
}
console.log(userList("Jhon", "Ram", "Nick")); // [ 'Jhon', 'Ram', 'Nick' ]
console.log(userList("Jhon")); //[ 'Jhon' ]

Now you can see there is no undefined error the values which you defined will collect it if not then no undefined.

Destructuring with Rest Operator

const fruits = ['apple', 'banana', 'cherry', 'date'];
const [first, second, ...rest] = fruits;

console.log(first);  // Output: 'apple'
console.log(second); // Output: 'banana'
console.log(rest);   // Output: ['cherry', 'date']

Refrence & premitive type variable assigning

In Primitive type data types (number, string, Symbol, bigint) these are immutable means in this variable the values are directly copied.

let x = 10;
let y = x; // y is now a copy of x's value
y = 20;    // changing y does not affect x

console.log(x); // 10
console.log(y); // 20

The reference type data type (array & object) not directly values are copied during variable assign there is referencing the pointer that is in memory it will more clearer from the below example.

let username = { name:"Rakesh Kumar" }
let username2 = username;
console.log(username);// Will print { name: 'Rakesh Kumar' }
console.log(username2); // Will print { name: 'Rakesh Kumar' }
username2.name="Jhon";
console.log(username);// Will print { name: 'Jhon' } but expected Rakesh Kumar
console.log(username2); // Will print { name: 'Jhon' }

In the above example the variable contains the name “Rakesh Kumar” Before manipulating the variable username2 was print { name: 'Rakesh Kumar' } but after changing the value in username2.name both are print { name: 'Jhon' } but we changed in username2 and username change itself. It happens because both are references to the same location. There is no direct copy of the values.

Now how can we fix this issue so that we can copy the values of one object to another and the original object should be the same or not any modification there? For this, we can use a spread operator.

let username = { name:"Rakesh Kumar" };
let username2 = {...username};
console.log(username);// Will print { name: 'Rakesh Kumar' }
console.log(username2); // Will print { name: 'Rakesh Kumar' }
username2.name="Jhon";
console.log(username);// Will print { name: 'Rakesh Kumar' }
console.log(username2); // Will print { name: 'Jhon' }

Array map and array filter in javascript es6

Array Map:

By giving each element of an existing array a function, the map() method generates a new array. Every element receives a new value from this method, which map() then aggregates into the new array. The original array and its values remain unchanged.

const numbers = [1, 2, 3, 4];
const multiplier = numbers.map(num => num * 2);
console.log(multiplier); // [2, 4, 6, 8]
console.log(numbers); // [1, 2, 3, 4] (original values unchanged)

Array filter

The name filter clearly states that the filter() used for filter the values of the array on the certain business logic or conditions. In this also original array and its values are not changed it creates a new array on the condition true.

const numbers = [1, 2, 3, 4, 5];
const evenNumbers = numbers.filter(num => num % 2 === 0);
console.log(evenNumbers); // [2, 4]
console.log(numbers);      // [1, 2, 3, 4, 5] (original array remains unchanged)

Conclusion

The complete post is written in keep min in javascript es6. It is a brief discussion about es6 concepts so that you can understand the latest framework and libraries like react, angular, Vue, and react. These front-end technologies are most popular those days but they all use modern javascript concepts. So, I hope you will enjoy the post and try to start learning new frameworks or libraries. Thanks for reading the article.

The post A Refreshing Dive into JavaScript ES6 Concepts appeared first on Postnidea.

Most of time designer & developer both are working on the WordPress projects. But if the designer has a little bit knowledge of PHP & WordPress basics then he can also complete project itself. In that case, an organization can save the developer efforts & the saved efforts can utilize on urgent tasks. Now today I have shown you few WordPress plugins can make your WordPress development faster.

Few important things need to do to start WordPress project.
– When you start WordPress installation then always use a unique prefix for the WordPress database table.
– Always set our custom keys
– Whenever you customize MySQL query then always use $wpdb->prefix.

1. Visual Composer

It’s paid plugin but it has most important features. A normal user can also design our website without the need of a designer. It’s already have so many shortcodes like the post, taxonomy, slider, apply CSS properties. There is a problem it saves page content in the database. So there is need to make changes very care full. Always need to enable page revision.

More Info

2. contact form 7 or gravity form

Forms are common parts of the web application. Contact form 7 & gravity form are two plugins that will helps the user in creating form. Contact Form 7 is a popular free plugin most of WordPress website use contact form 7. Gravity form has extra features due to these features it’s paid. In Both form plugin, you can integrate our custom HTML
More Info More Info

3. woocommerce

E-commerce & blog a normal requirement of client every client. WordPress already have blog functionality. But not have e-commerce functionality. So, for implement e-commerce, there is need to add another plugin. So, woocommerce is a plugin that enables e-commerce functionality. It’s very old plugin so it has a huge amount of support.

More Info

4. Yoast SEO

Once the website is complete then marketing of a website is very important. If the website can’t generate the revenue and customer then it’s not beneficial. For search engine optimization purpose on page optimization very important. It will help in SEO. Yoast SEO plugin which enables the SEO features on your WordPress project.

More Info

5. Custom Post Type Maker

When you start the custom application in WordPress then always a requirement of a custom post like a portfolio, team, etc. So “Custom Post Type Maker” plugin which helps to create custom post type & taxonomy.

More Info More Info

6. advanced custom field

It’s the plugin which extends you custom post functionality. With the help of them, you can create the meta fields, repeater fields. It provides an easy interface so that non-developer user can also extend the project functionality.
More Info

7. Fast cache

It will help in the performance of your WordPress project. It enables cache on your project so that most of the pages serve for the customer from the cache so, that your server or hosting resource become save. In short, you can get great performance with short of resources. If you can afford paid version then you can get the CDN & database optimization & cache features.

More Info

8. wp security

Once your website is ready & running in live mode or real world then security is very important. If your website down for a day then it’s a retarded lot of revenue even left bad impressions on the visitors. wp security plugin which provides the various types of security like file security, database security, login lockdown session exploiting & many more.

More Info

9. migrate DB

It’s common plugin used by most of the developer’s because when you try to replicate current working website on our local then it provides you database according to your local URL. Mainly it helps in replacement of the URLs. So that you set up website locally faster.

More Info

10. qTranslate X or WPML

If your website is multi-language then above both plugin great helps in translating. You can provide the translation for each language so that it will show the translated string for your user according to their locality.

More Info

11. BuddyPress

It helps to create networking website. Its provide a great feature of social networking website like activity, share, groups, pages & create connections between each other. You can also extend their functionality by overriding theme or plugin.

More Info

The post Top 10 WordPress plugin make development faster appeared first on Postnidea.

For any product, document ion is very important. When you develop a product then only you know how its work & how to use. But if someone new person tries to use then he can’t use it so, in that case, your product useless for the user. So whenever you develop any product there is need to create a proper documentation. The documentation should cover below points.

About product

In this section describe our product completely like “about product”, “Why you made it”. If you develop something new product then there is no need to a comparison. If some product already exists then there is a need for comparison so that user can compare it. If a user uses an already product and your product have something new and better than user remve/uninstall our product & try your, In that situation, if your product works better than user always use your product if he fails then he use our existing product. So there more important to include about a product, advantage, disadvantage last but not least comparison.

How to use it

It’s very important section so it’s documented very carefully. There is need to clarify more clearly so that user can easily understand. There is a need for more graphics & text so that user have a clear idea. If your product is digital then nowadays different platforms like youtube, SlideShare, GitHub can help you. This platform provide you an area in which you show graphics, picture & animation so that product user can easily understand & use it.

Reviews

In this section provide the way (review submit form, toll-free number, or any number) through which user can provide the reviews. With the help of reviews, you can improve your product. Because mistakes make perfect so it’s more important.

I review many plugins of WordPress the author writes very good & usable plugins but they fail only the documentation. Now WordPress provide a help section on top of the screen so take help of that you can provide help text & animation on each page.

start with creating simple, so I write code for creating a plugin which is below

Now the plugin is created but only its shows in the plugin list now there is a need to links on sidebar menu so that user can move on the pages by clicking on that. Now below code add two menus in admin sidebar menu. The below menu also connected with function my_magic_function & my_magic_function1.

Now Menu appears in the sidebar now on click on menu need to redirect on the page now I write a below code which creates the page on which user can redirect.

Now everything gone fine now the small plugin is ready but there is scanty of documentation now below code add the help text in above screen.

Now when you install this plugin in our wordpress set up then you can see the demo. I also attached the youtube video on which you also see the demo.

You can also browse the complete code by click on next button
code

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