Tuesday, March 14, 2017

VBScript - Overview

VBScript stands for Visual Basic Scripting that forms a subset of Visual Basic for Applications (VBA).
VBA is a product of Microsoft which is included NOT only in other Microsoft products such as MS Project and MS Office but also in Third Party tools such as AUTO CAD.

Your First VBScript

Let us write a VBScript to print out "Hello World".

<html>
<body>
<script language="vbscript" type="text/vbscript">
   document.write("Hello World!")
</script>
</body>
</html>

Enabling VBScript in Browsers

NOT All the modern browsers support VBScript. VBScript is supported just by Microsoft's Internet Explorer while other browsers(Firefox and Chrome) just support JavaScript. Hence, the developers prefer JavaScript over VBScript.

VBScript Placement in HTML File

There is a flexibility given to include VBScript code anywhere in an HTML document. But the most preferred way to include VBScript in your HTML file is as follows:

Script in <head>...</head> section.
Script in <body>...</body> section.
Script in <body>...</body> and <head>...</head> sections.
Script in an external file and then include in <head>...</head> section.

VBScript Variables

Variable is a named memory location used to hold a value that can be changed during the script execution. VBScript has only ONE fundamental data type, Variant.
Rules for Declaring Variables:

VBScript - Constants

Constant is a named memory location used to hold a value that CANNOT be changed during the script execution. If a user tries to change a Constant Value, the Script execution ends up with an error. Constants are declared the same way the variables are declared.

What is an operator?

Simple answer can be given using expression 4 + 5 is equal to 9. Here, 4 and 5 are called operands and + is called operator. VBScript language supports following types of operators:

Arithmetic Operators
Comparison Operators
Logical (or Relational) Operators
Concatenation Operators

VBScript - Decision Making

Decision making allows programmers to control the execution flow of a script or one of its sections. The execution is governed by one or more conditional statements.
Following is the general form of a typical decision making structure found in most of the programming languages:

VBScript - Loops

There may be a situation when you need to execute a block of code several number of times. In general, statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.

What is an Event ?

VBScript's interaction with HTML is handled through events that occur when the user or browser manipulates a page.
When the page loads, that is an event. When the user clicks a button, that click too is an event. Another example of events are like pressing any key, closing window, resizing window, etc.

What are Cookies?

Web Browser and Server use HTTP protocol to communicate and HTTP is a stateless protocol. But for a commercial website, it is required to maintain session information among different pages. For example, one user registration ends after completing many pages. But how to maintain user's session information across all the web pages.

Description

Number functions help the developers to handle numbers in an efficient way and also helps them to convert their subtypes. It also helps them to make use of the inbuilt mathematical functions associated with VBscript.

VBScript - Strings

Strings are a sequence of characters, which can consist of alphabets or numbers or special characters or all of them. A variable is said to be a string if it is enclosed within double quotes " ".

What is an Array?

We know very well that a variable is a container to store a value. Sometimes, developers are in a position to hold more than one value in a single variable at a time. When a series of values are stored in a single variable, then it is known as array variable.

VBScript - Date and Time Functions

VBScript Date and Time Functions help the developers to convert date and time from one format to another or to express the date or time value in the format that suits a specific condition.

What is a Function?

A function is a group of reusable code which can be called anywhere in your program. This eliminates the need of writing same code over and over again. This will enable programmers to divide a big program into a number of small and manageable functions.

What is a Dialog Box ?

VBScript allows the developers to interact with the user effectively. It can be a message box to display a message to a user or an input box with which user can enter the values.

What is an Object

VBScript runtime objects help us to accomplish various tasks. This section will help you understand how to instantiate an object and work with it.

What are Regular Expressions?

Regular Expressions is a sequence of characters that forms a pattern, which is mainly used for search and replace. The purpose of creating a pattern is to match specific strings, so that the developer can extract characters based on conditions and replace certain characters.

VBScript - Error Handling

There are three types of errors in programming: (a) Syntax Errors and (b) Runtime Errors (c) Logical Errors.

Syntax errors

Syntax errors, also called parsing errors, occur at interpretation time for VBScript. For example, the following line causes a syntax error because it is missing a closing parenthesis:

<script type="text/vbscript">

VBScript Miscellaneous Statements

There are few other important statements which helps the developers to develop an efficient script. Below are the list of statements tabulated and explained in detail with examples.

VBScript Questions and Answers

VBScript Questions and Answers has been designed with a special intention of helping students and professionals preparing for various Certification Exams and Job Interviews. This section provides a useful collection of sample Interview Questions and Multiple Choice Questions (MCQs) and their answers with appropriate explanations.

VBScript - Useful Resources

The following resources contain additional information on VBScript. Please use them to get more in-depth knowledge on this topic.

Discuss VBScript

Microsoft VBScript (Visual Basic Script) is a general-purpose, lightweight and active scripting language developed by Microsoft that is modelled on Visual Basic. Nowadays, VBScript is the primary scripting language for Quick Test Professional (QTP), which is a test automation tool.

TypeScript - Overview

JavaScript was introduced as a language for the client side. The development of Node.js has marked JavaScript as an emerging server-side technology too. However, as JavaScript code grows, it tends to get messier, making it difficult to maintain and reuse the code.

Try it Option Online
We already have set up TypeScript programming online, so that you can execute all the available examples online at the same time when you are doing your theory work. This gives you confidence in what you are reading and to check the result with different options. Feel free to modify any example and execute it online.

TypeScript - Basic Syntax

Syntax defines a set of rules for writing programs. Every language specification defines its own syntax. A TypeScript program is composed of −

Modules
Functions
Variables
Statements and Expressions
Comments

TypeScript - Types

The Type System represents the different types of values supported by the language. The Type System checks the validity of the supplied values, before they are stored or manipulated by the program. This ensures that the code behaves as expected. The Type System further allows for richer code hinting and automated documentation too.

TypeScript - Variables

A variable, by definition, is “a named space in the memory” that stores values. In other words, it acts as a container for values in a program. TypeScript variables must follow the JavaScript naming rules −

Variable names can contain alphabets and numeric digits.
They cannot contain spaces and special characters, except the underscore (_) and the dollar ($) sign.
Variable names cannot begin with a digit.

What is an Operator?

An operator defines some function that will be performed on the data. The data on which operators work are called operands. Consider the following expression −
7 + 5 = 12
Here, the values 7, 5, and 12 are operands, while + and = are operators.
The major operators in TypeScript can be classified as −

TypeScript - Decision Making

Decision-making structures require that the programmer specifies one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.

TypeScript - Loops

You may encounter situations, when a block of code needs to be executed several number of times. In general, statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.

TypeScript - Functions

Functions are the building blocks of readable, maintainable, and reusable code. A function is a set of statements to perform a specific task. Functions organize the program into logical blocks of code. Once defined, functions may be called to access code. This makes the code reusable. Moreover, functions make it easy to read and maintain the program’s code.

TypeScript - Numbers

TypeScript like JavaScript supports numeric values as Number objects. A number object converts numeric literal to an instance of the number class. The Number class acts as a wrapper and enables manipulation of numeric literals as they were objects.

TypeScript - Strings

The String object lets you work with a series of characters. It wraps the string primitive data type with a number of helper methods.

TypeScript - Arrays

The use of variables to store values poses the following limitations −

Variables are scalar in nature. In other words, a variable declaration can only contain a single at a time. This means that to store n values in a program n variable declarations will be needed. Hence, the use of variables is not feasible when one needs to store a larger collection of values.

TypeScript - Tuples

At times, there might be a need to store a collection of values of varied types. Arrays will not serve this purpose. TypeScript gives us a data type called tuple that helps to achieve such a purpose.
It represents a heterogeneous collection of values. In other words, tuples enable storing multiple fields of different types. Tuples can also be passed as parameters to functions.

TypeScript - Union

TypeScript 1.4 gives programs the ability to combine one or two types. Union types are a powerful way to express a value that can be one of the several types. Two or more data types are combined using the pipe symbol (|) to denote a Union Type. In other words, a union type is written as a sequence of types separated by vertical bars.

TypeScript - Interfaces

An interface is a syntactical contract that an entity should conform to. In other words, an interface defines the syntax that any entity must adhere to.
Interfaces define properties, methods, and events, which are the members of the interface. Interfaces contain only the declaration of the members. It is the responsibility of the

TypeScript - Objects

An object is an instance which contains set of key value pairs. The values can be scalar values or functions or even array of other objects. The syntax is given below −

Syntax

var object_name = { 
   key1: “value1”, //scalar value 
   key2: “value”,  
   key3: function() {
      //functions

TypeScript - Namespaces

A namespace is a way to logically group related code. This is inbuilt into TypeScript unlike in JavaScript where variables declarations go into a global scope and if multiple JavaScript files are used within same project there will be possibility of overwriting or misconstruing the same variables, which will lead to the “global namespace pollution problem” in JavaScript.

TypeScript - Modules

A module is designed with the idea to organize code written in TypeScript. Modules are broadly divided into −

Internal Modules
External Modules

TypeScript - Ambients

Ambient declarations are a way of telling the TypeScript compiler that the actual source code exists elsewhere. When you are consuming a bunch of third party js libraries like jquery/angularjs/nodejs you can’t rewrite it in TypeScript.

TypeScript - Overview

TypeScript - Useful Resources

The following resources contain additional information on TypeScript. Please use them to get more in-depth knowledge on this.

Discuss TypeScript

TypeScript lets you write JavaScript the way you really want to. TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. TypeScript is pure object oriented with classes, interfaces and statically typed like C# or Java.

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Tuesday, March 14, 2017

Your First VBScript

VBScript Placement in HTML File

VBScript Variables

What is an operator?

What is an Event ?

What are Cookies?

Description

What is an Array?

What is a Function?

What is a Dialog Box ?

What is an Object

What are Regular Expressions?

Syntax errors

Try it Option Online

What is an Operator?

Syntax

TypeScript - Overview