By: aathishankaran in JavaScript Tutorials on 2007年03月21日 [フレーム]
JavaScript is but a scripting language, not a tool in and of itself. The software that actually runs the JavaScript code you write is the Web browser. JavaScript depends on the Web browser to support it. If the browser does not support it, your code will be ignored. Even worse, if you do not account for unsporting browsers, the JavaScript code itself is displayed as text on your page.
Commonly available Browser are:
As with most scripting languages,. JavaScript is interpreted at runtime by the browser before it is executed. JavaScript is not compiled into an actual program like an .EXE file but remains part of the HTML document to which it is attached.
The disadvantage of an interpreted language is that it takes longer for the code to execute because the browser compiles the instructions at runtime just before executing them. However, the advantage is that it is much easier to update your source code. You do not have to worry about old versions of a JavaScript script hanging around because if you change it in your source HTML file, the new code is executed the next time the user accesses the document.
JavaScript is far different from strong-typed languages such as Java or Delphi, in which you must declare all variables of a certain type before using them. In contrast, JavaScript is much more flexible. You can declare variables of a specific type, but you do not need to. You can also work with a variable when you might not know the specific type before run time.
You might see JavaScript referred to as an object-oriented programming (OOP) language by Netscape and others, but this is actually a stretch of the true meaning of OOP. JavaScript is really an object-based language.
Much of the JavaScript code you write will be in response to events generated by the user or the system. The JavaScript language itself is equipped to handle events. HTML objects, such as buttons or text fields, are enhanced to support event handlers.
JavaScript is multifaceted and can be used in a variety of contexts to provide a solution to a Web-based problem. Uses of JavaScript are:
This policy contains information about your privacy. By posting, you are declaring that you understand this policy:
This policy is subject to change at any time and without notice.
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
Most Viewed Articles (in JavaScript )
Dynamically modify the option set in Dynamics 365 forms
promise and .then() in JavaScript
reduce() and filter() in JavaScript
History and evolution of Javascript
Using parseInt() and parseFloat() in JavaScript to convert data types to Numbers
Show how many characters remaining in a html text box using javascript
Latest Articles (in JavaScript)
© 2023 Java-samples.com
Tutorial Archive: Data Science React Native Android AJAX ASP.net C C++ C# Cocoa Cloud Computing EJB Errors Java Certification Interview iPhone Javascript JSF JSP Java Beans J2ME JDBC Linux Mac OS X MySQL Perl PHP Python Ruby SAP VB.net EJB Struts Trends WebServices XML Office 365 Hibernate
Latest Tutorials on: Data Science React Native Android AJAX ASP.net C Cocoa C++ C# EJB Errors Java Certification Interview iPhone Javascript JSF JSP Java Beans J2ME JDBC Linux Mac OS X MySQL Perl PHP Python Ruby SAP VB.net EJB Struts Cloud Computing WebServices XML Office 365 Hibernate