In a script (or program), constant data and variable data are used that change values during program execution. These data are called variables. Variable = the name of a location in the computer’s memory used to store data. The easiest way to use and refer to such a variable date is to name it. The variable name allows access to its value as well as changing the value if necessary. You...
Forms are HTML elements that give life to static pages because they provide an interface through which visitors can interact with controls (form elements). The Form object is how you can interact with this HTML element in your JavaScript scripts. 1. Methods and properties of the object The properties of the “Form” object are as follows: action – contains the “action”...
Using JavaScript, you can create a lot of effects on the images on the site. In JavaScript, all images are represented in a matrix called images. This is a property (and sub-object) of the “document” object. For indexing in the array (or array), each image on a web page has a certain number (index). The first image has the number 0; the second image has the number 1 and so on. Thus...
Windows are the most important interface elements in the browser, and JavaScript offers many ways to manipulate them. 1. Properties and methods of the window object. A browser (regardless of the name or manufacturer) is displayed in a window and everything the user does with the browser runs inside that window. All elements of a web page are also contained in that window. The “Window”...
Objects are crucial to building complex and efficient Java applications. When a developer creates a complex system, the process design begins, dividing the various project requirements into component applications. In the last phase, they are represented by objects in the application and are implemented in the code by class declarations. It might be difficult to see the benefits of this technique...
Debuggers are sophisticated programs that allow the execution of other applications in a controlled manner; they allow the execution, observation and modification of another program. Debuggers use a variety of techniques related to fault isolation software, and tool support that generates programs and operating system. Debuggers behave against the debugging program similar to some interpreters...
Sometimes the unfortunate situation appears when a program begins to store memory for no obvious reason. The effect is usually noticed only after all of the computer’s memory fills up, and the system becomes unstable. The situation occurs when a programmer forgets to release dynamic memory for variables in the program. Sometimes, the working context can be quite complicated, and the number...
Integrated Development Environments (IDEs) are complex applications used by programmers, apps that provide access to tools. IDE runs a range from simple to incredibly sophisticated, some looking for an uninterrupted UI interface in an easy tool to maximize speed for smaller tasks, and others that provide multi-lingual support in more robust environments manipulation of more complicated...
The Linux kernel is the most essential part of the OS, the one that works with the CPU and is the closest to the hardware level. Physically the Kernel is found in a file, and most of the time it is /boot/vmlinuz.version.no. In 1991, Linus Torvalds, a student at the University of Helsinki, Finland, began working on what was called kernel 0.02. No one believed then that this would be the basis for...
It represents the state in which the operating system is and operates at a given time. Example: A Linux operating system that enters run level 0 will stop, while if it enters run level 6 it is just restarting. Depending on the runlevel in which the operating system goes, there are certain facilities offered and certain running processes. A Linux operating system can be at in a given moment in a...