ES6 stands for ECMAScript6. ES6 was released in 2015 and is also known as the ECMAScript 2015. It is basically a standard, which the scripting languages have to follow.

As we know, Javascript is a scripting language. JS also follows ES6 standards. ES6 helps to standardize JS. After ES6, JS got many new features like let keyword, Arrow functions, Rest and Spread Operators, Classes, Array and object destructuring, default parameters and the list goes on. These newly introduced features are very much useful to minimize the no. of lines of code.

React ES6

React Js is a Javascript library, which is used for creating single page applications. The reason for React Js’s popularity is its features like code reusability, single page application.

React ES6 is the combination of React and ES6 standards. React Js was first inroduced in year 2013. Since then it got many features, one of which is the adoption of ES6 syntax. ES6 syntax makes the code more precise and concise. For example, Use of Arrow functions instead of regular functions.

In the above example both the function performs the same addition operation, but sum2 (Arrow function) is a more cleaner way to write the code.

Features of React ES6

React ES6 includes many new features, which are listed below :-

• Classes and objects
• Rest and spread operators
• Array and object destructuring
• let and const keyword
• Array methods like .map(), .filter() and .reduce()

Difference between ES6 and ES5

The post React ES6 appeared first on MaXEster Technologies | Technical Blog.

The below code contains an array of JSON values

these JSON values are URL and respective id

URL is tho fetch data and ID is to append data

    s = [{
		url : "url1",
		id : "id1"
	},{
		url : "url2",
		id : "id2"
	},{
		url : "url3",
		id : "id3"
	},{
		url : "url4",
		id : "id4"
	}]

now calling all these URL in .each()

$(s).each(function() {
	var url = this.url, id = this.id;
	$.getJSON(url, {id: id }).done( function(data) {
		$(data.id).append(data.value)
	});
})

The post Parallel ajax request using Jquery appeared first on MaXEster Technologies | Technical Blog.

“replace()” is a iterative function calling a regex as first parameter and adding callback function as its second parameter we can achieve this.

Regular Expression for Every Word in a String ( /\w\S*/g )

And

Callback function converts first word of every word to Upper case

var text = "how to capitalize first letter of each word in js ?";

function toTitleCase(str) {
    return str.replace(/\w\S*/g, function(txt){
        return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
    });
}

text = toTitleCase(text);

//output
//How To Capitalize First Letter Of Each Word In Js ?

For es6:

var text = "how to capitalize first letter of each word in js ?";

upperCaseWords = (s => s.toLowerCase().split(" ").map(s => s.charAt(0).toUpperCase() + s.substring(1)).join(" "));
    
text = upperCaseWords(text)

//output
//How To Capitalize First Letter Of Each Word In Js ?

The post How To Capitalize First Letter Of Each Word In Js ? appeared first on MaXEster Technologies | Technical Blog.

To prevent repeating the code and make it more maintainable we define it as a function in one place.

That is what this blog is about.

Prerequisite

• jQuery
• jQuery Validation Plugin

Create a js file

var $postJobValidation = {
	id: function(e) {
		$("#" + e).validate({
			rules: this.rules,
			messages: this.messages
		})
	},
	set: function(e) {

		if (e) {
			for (t in e) {

				if (e[t].rule)
					this.rules[t] = e[t].rule

				if (e[t].message)
					this.messages[t] = e[t].message
			}
		}
	},
	rules: {
		name: "required",
		email: {
			email: !0,
			required: !0
		},
	},
	messages: {
		name: "PLease Enter Your Name",
		email: {
			email: "Enter Valid Email!",
			required: "Enter Email!"
		},
	}
};

To validate a form with id “form1” and having fiels name and email.

$formValidation.id("form1")

To add rules and message we just need to edit rules and message object in $formValidation

$postJobValidation.set({
	"contact": {
		rule: "required",
		message: "Please Enter Your Contact"
	}
})

Set function iterates through the json provided and adding rules

The post Dynamic web form validation with predefined rules and messages appeared first on MaXEster Technologies | Technical Blog.

let the response be:

[{
    "data1": "male",
    "data2": "23",
    "data3": "Delhi",
    "data4": "10+2 or above"
}, {
    "data1": "male",
    "data2": "40",
    "data3": "Delhi",
    "data4": "Diploma"
}, {
    "data1": "male",
    "data2": "31",
    "data3": "Delhi",
    "data4": "Graduation"
}, {
    "data1": "male",
    "data2": "25",
    "data3": "Delhi",
    "data4": "Post Graduation"
}]

let the response is saved in var response

let the place where response is appended is

<div><table id="append"></table></div>

to append the json store in data to “#append”

$("#append").append(response.map(data => `<tr><td>${data.data1}</td><td>${data.data2}</td><td>${data.data3}</td><td>${data.data4}</td></tr>`))

Jquery append function is an iterative function which will call response.map which will call parse json

The post Json parsing to add an iterating element by Jquery appeared first on MaXEster Technologies | Technical Blog.

Node has an inbuilt event module about which you learn in-depth from here, we will use event listener and event emitter method of this class.

const EventEmitter = require('events');

const event = new EventEmitter();

Event Listener

An event listener is a logic which will be executed when an event is emitted. Make sure you have declared Event listener before emitting the event.

event.on('some-event', function() {
  // some logic
});


//es6
event.on('some-event', () => {
  // some logic
});


//with parameter
event.on('some-event', (parameter) => {
  // some logic
});

Event Emitter

Event emitter is used to trigger a specific event listener.

event.emit('some-event', parameter);

The post Node Event Module appeared first on MaXEster Technologies | Technical Blog.

It return type is true value is kept in the array if false value is removed.

Lets have an example to understand its implementation.

let arr1 = [6, 1, 3, 2, 8, 1, 7, 5, 9 ,9];

As you can see arr1 is an array with values 1-9 with non unique values.

to get values greater than 4

a.filter(x => x>4)
// output [6, 8, 7, 5, 9, 9]

Sort – High order function used to sort values in asc or desc order.

Lets have an example to understand its implementation.

let arr2 = [6, 1, 3, 2, 8, 1, 7, 5, 9 ,9];

As you can see arr2 is an array with values 1-9 with non unique values.

to get values in asc order

arr2 = arr2.sort()
//output [1, 1, 2, 3, 5, 6, 7, 8, 9, 9]

to get values in desc order

arr2 = arr2.sort( (a, b) => b - a );
//output [9, 9, 8, 7, 6, 5, 3, 2, 1, 1]

for string

to get values in asc order

let arr3 = ['a', 'b', '25', '100'];
arr3 = arr3.sort( (a, b) => a < b ? -1 : 1 );
// output ["100", "25", "a", "b"]

as you can see 100 is shown smaller than 25 as sort compares 1 to 2 and 1 is clearly smaller than 2 and rest are arranged in alphabetical order as in a Dictionary

The post Js Filter And Sort appeared first on MaXEster Technologies | Technical Blog.

ANDoperator (&&) returns first false for false value and last true for true values.

But,

OR operator (||) returns first true for truely statement and last false for false statement.

So, for

Falsely statement

console.log( 0 || [] );
//returns [] as it is last false 

console.log( 0 || [] );
//returns 0 as it is first false 

Truely statement

console.log( 1 || 0 || 3 );
//returns 1 as it is first true 

console.log( 1 || 2 || 3 );
//returns 0 as it is last true

NOTE:- In JS all values are true except ( 0, “”, undefined, null and false)

Bitwise operators like( |, & )

bit wise operators use to perform binary operations like bitwise or ( binay add ) and bitwise and ( binary multiplication )

so,

console.log( 3 | 2 )
// returns 3 as binary sum of 011 and 010 is 011

console.log( 3 & 2 )
// returns 2 as binary sum of 011 and 010 is 010

The post What is Short-Circuit Evaluation in JS? appeared first on MaXEster Technologies | Technical Blog.

Well you can do it by calling a closure in default parameter which can throw error for you.

This practice is good if you are having a lot of function with required parameters to debug what went wrong quickly. Otherwise it you can simply show an error from inside the function

const isRequired = (message = null) => {
 let err = (message == null || message.length < 2) ? 'param is required' : `${message[0]} param is required in ${message[1]} function`;
 throw new Error();
};

const myFunction = (param1 = isRequired(['name', 'myFunction'])) => {
 console.log(`param: ${param1}`)
};

// These will throw an error
myFunction();
myFunction(undefined);

// These are work!
myFunction(null);
myFunction('Maxester');

The post How to Require Function Parameter in JS? appeared first on MaXEster Technologies | Technical Blog.

Rules are the validation case that you want to check on an input field.

And, Messages are the response to those input field which violates the rules.

Jquery validation uses name instead of id for validation.

$("#form_id").validate({
rules:{
	name:"required",
	email:{email: true,required: true},
	mobile:{required : true,minlength:10},

},

messages: {
	name:"Please fill name",
	email:{email:"Enter Valid Email!",
		required:"Enter Email!"
		},
	mobile:{minlength:"Please enter Valid Mobile No.",
		required:"Please enter Mobile No."
		},
},

submitHandler: function(form){
$.ajax({
	url: form.action,
	type: form.method,
	data: $(form).serialize(),
	success: function(response) {
		$('#answers').html(response);
	}            
      });		
}
});

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