Datatype Library Javascript Html5

Posted on 05.08.2019

Data Types In Javascript
Data Type Library Javascript Html5 Player
Data Type Library Javascript Html5 File

JavaScript Datatypes

One of the most fundamental characteristics of a programming language is the set of data types it supports. These are the type of values that can be represented and manipulated in a programming language.

$(function var pivotGridDataSource = new DevExpress.data.PivotGridDataSource( store: //. // Underlying store is configured here //. Print.js is a tiny javascript library to help printing from the web. Print friendly support for HTML elements, image files and JSON data. Print PDF files directly form page. There are two types of data types in JavaScript. Primitive data type; Non-primitive (reference) data type; JavaScript is a dynamic type language, means you don't need to specify type of the variable because it is dynamically used by JavaScript engine. You need to use var here to specify the data type. It can hold any type of values such as.

JavaScript allows you to work with three primitive data types −

Numbers, eg. 123, 120.50 etc.
Strings of text e.g. 'This text string' etc.
Boolean e.g. true or false.

JavaScript also defines two trivial data types, null and undefined, each of which defines only a single value. In addition to these primitive data types, JavaScript supports a composite data type known as object. We will cover objects in detail in a separate chapter.

Note − JavaScript does not make a distinction between integer values and floating-point values. All numbers in JavaScript are represented as floating-point values. JavaScript represents numbers using the 64-bit floating-point format defined by the IEEE 754 standard.

JavaScript Variables

Like many other programming languages, JavaScript has variables. Variables can be thought of as named containers. You can place data into these containers and then refer to the data simply by naming the container.

Before you use a variable in a JavaScript program, you must declare it. Variables are declared with the var keyword as follows.

You can also declare multiple variables with the same var keyword as follows −

Storing a value in a variable is called variable initialization. You can do variable initialization at the time of variable creation or at a later point in time when you need that variable.

For instance, you might create a variable named money and assign the value 2000.50 to it later. For another variable, you can assign a value at the time of initialization as follows.

Note − Use the var keyword only for declaration or initialization, once for the life of any variable name in a document. You should not re-declare same variable twice.

JavaScript is untyped language. This means that a JavaScript variable can hold a value of any data type. Unlike many other languages, you don't have to tell JavaScript during variable declaration what type of value the variable will hold. The value type of a variable can change during the execution of a program and JavaScript takes care of it automatically.

JavaScript Variable Scope

The scope of a variable is the region of your program in which it is defined. JavaScript variables have only two scopes.

Global Variables − A global variable has global scope which means it can be defined anywhere in your JavaScript code.
Local Variables − A local variable will be visible only within a function where it is defined. Function parameters are always local to that function.

Within the body of a function, a local variable takes precedence over a global variable with the same name. If you declare a local variable or function parameter with the same name as a global variable, you effectively hide the global variable. Take a look into the following example.

Live Demo

This produces the following result −

JavaScript Variable Names

While naming your variables in JavaScript, keep the following rules in mind.

You should not use any of the JavaScript reserved keywords as a variable name. These keywords are mentioned in the next section. For example, break or boolean variable names are not valid.
JavaScript variable names should not start with a numeral (0-9). They must begin with a letter or an underscore character. Maintenant on l'appelle plata streaming vf sub. For example, 123test is an invalid variable name but _123test is a valid one.
JavaScript variable names are case-sensitive. For example, Name and name are two different variables.

JavaScript Reserved Words

A list of all the reserved words in JavaScript are given in the following table. They cannot be used as JavaScript variables, functions, methods, loop labels, or any object names.

abstract	else	instanceof	switch
boolean	enum	int	synchronized
break	export	interface	this
byte	extends	long	throw
case	false	native	throws
catch	final	new	transient
char	finally	null	true
class	float	package	try
const	for	private	typeof
continue	function	protected	var
debugger	goto	public	void
default	if	return	volatile
delete	implements	short	while
do	import	static	with
double	in	super

How to populate a HTML5 table if you receive data in JSON format in jQuery Ajax and based on a specific column on a row color that row on a table (Using bootstrap 4 CSS styles?)

For example if i receive a dataset in JSON format like this:

The column city is New York so the table row should be colored green so the finished product should be like this:

I'm fairly new at jQuery can anyone guide me through how this can be achieved?

I'm using datatables library at the moment and what i have done is this:

Current HTML5 code is displayed bellow

But when I click the button no data rows are returned by the browser (SQL Server does return data). Also as i mentioned i do not know how to accomplish that if specific data is returned in a row i need to color it..

Thank you for your help in advance..

Shiladitya

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3 Answers

Aniruddha Das

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BalwantBalwant

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For using DataTables with ajax you usually have something like this:

As you can see the plugin itself has the functionality to use ajax.

So by default your returned data from server should contain a property data which contains the elements that are about to be rendered. You can actually specifiy this by using the dataSrc (reference) prop of ajax, you can set it to other name or remove it if you use plain collection:

This however does not change the data name in columns declaration so don't change it there.

You can read more about accepted formats and see examples in the official documentation.

Now regarding your question about row styling, there are a lot of callbacks and declarations which you can use to achieve that. I personally prefer using the createdRow callback (reference):

So in this case if the age (second column based on 0-start-indexing) of the current row is above 18 it will add the desired class.

Data Types In Javascript

I hope this helps resolving your issues, if there still are problems you can try making a working jsfiddle so we can try debugging it in a 'real-like' situation.