JavaScript Unknown Value Options

JavaScript deals with unknown data values in different forms. Developers could build any function of the application freely but when they are not according to the specifications of the browser, it can return in two forms. These forms have their distinct functions which should be considered by developers. 

This is the major difference of JavaScript compared to other programming languages – instead of going back with a simplified “error” function, the browser could come back with two forms: “null” and “undefined.” These functions have distinct meanings which gives the developers an idea on what they should do with the application.

The “null” error

Null is the common error developers would face when dealing with an Ajax based application. This type of error could be greatly tied with the JavaScript interpretation in the browser being implemented or in the coding itself.

When the application returns with a “null” response in certain functions, developers have to check two things:

• Browser compatibility – There are certain functions in an Ajax and JavaScript based application that can’t be easily read by the browser. IE should be double checked by developers especially when the application is DOM intensive. There are many functions tied to DOM such as node and childnode interpretation that might not run easily in different browsers.

• Coding – If the browser can interpret the function well but still returns with a null, developers have to make some changes in their function. Although the function is technically correct, null signifies that the function doesn’t have the right object. When null happens, the value is not properly identified.

Considering “undefined” error

When a developer sees an “undefined” error in the application’s coding, developers have to seriously consider changing the coding. “Undefined” is usually encountered by developers if the function is not finished yet. The “undefined” error should mean the coding is either not finished or the function is totally wrong. The main problem when developers encounter an “undefined” error is that variables and not specifically set.

To properly deal with this problem, certain functions have to be properly checked before looking into the specific problem. There are times that functions may not synch with the function that have yielded the “undefined” error. This means that the problem is not based on the error itself but on other functions that have not yielded the expected variable.

Applying the “delete” function

There are situations wherein the developer has to purposely “undefine” the function. This is a little bit tricky considering “undefined” is already an error. But developers could actually implement “undefined” in their function by implementing an operator called delete.

The “delete” operator will automatically disable the variables to be interpreted by JavaScript. Developers often use this since when they don’t want the variables to be explicitly known in their application. There are times when the variables just have to be implied within the application instead of making them public.

“Null” and “undefined” are two error codes that should be considered significantly by developers if they want to build an efficient Ajax based application. They signify certain errors either in browser compatibility or in coding.