Differences between JavaScript, JScript, VBScript, and ASP

Many people are confused by these terms. Here we will make an induction to thoroughly clarify these concepts.

Javascript

Javascript was first developed by Netscape, formerly called livescript.LanguageThe Java language was very popular at that time, so it was renamed JavaScript soon. Netscape implements the language on its Web browser and applies it to client development.

JScript

I have to mention VBScript, a Microsoft product. Its syntax is weird (for JavaProgramPersonnel), lack of support for the concept of OOP, and other reasons, leading to VBScript complaints, So Microsoft, with great wealth of money, modeled on the new client language JavaScript to create a JScript from the home, hoping to seize the market. Currently, JavaScript and JScript are almost identical.

VBScript

As mentioned above, VBScript is a Microsoft product and is applied to client development at the beginning. After the concept of dynamic scripts (ASP came out), Microsoft implemented the concept of dynamic scripts for the product and its own JScript Language.

ASP

ASP stands for Active Server Page. It is a technology rather than a language. Currently, most ASP instances use VBscript. The default language of server IIS is VBScript. Since there is a default language, it indicates that there is a non-default language. That is, JScript. As mentioned earlier, JScript can also be applied to the server, or even completely replace VBScript and operate databases.
That is to say, VBScript and JScript can be applied both on the client and on the server. Take a look at the following example:
<Script language = "VBScript">
<! --
// Client script vbs
Response. Write "demo text..." // case-insensitive, syntax quite loose
-->
</SCRIPT>

<Script language = "JavaScript">
<! --
// Client script JS
Document. Write ("demo text...") // the built-in object must be case sensitive.
-->
</SCRIPT>

<Script language = "VBScript" runat = "server">
<! --
// Server script vbs
Response. Write "demo text..." // case-insensitive, syntax quite loose
-->
</SCRIPT>

<Script language = "JavaScript" runat = "server">
<! --
// Server script JS
Response. Write ("demo text...") // ASP built-in object must be case sensitive -->
</SCRIPT>
Or:
<% @ Language = "JavaScript" %> // place it on the first line of the server page, indicating that the page uses JavaScript scripts by default and <% 'Code... %>, the interpreter thinks this is the language defined in the first line.
<% @ Language = "VBScript" %> // The first line on the server page, indicating that the page uses the VBScript and the <% 'Code... %>, the interpreter thinks this is the language defined in the first line.

In addition,. vbs and. js can be interpreted and run by window Script Host (wsh ).