Document all is undefined javascript

body> script type="module" src="index.js"> script> body>
Code language: HTML, XML (xml)

Catching the error

Here we will discuss ways to catch this error so that you know exactly when and where to look for it. If we execute the code on the front end, and the DOM exists, so will the document object exist. Therefore, in other scenarios, if we look closely at the error, it says: document is not defined. Thus, the document object value will be “undefined.” We can check this by console logging the value of the document (always a tremendous debugging practice!) We utilize this to check for this error and catch it.

Using just a simple if-else statement, we will be able to check for this error. We can do this in the code modeled below:

if (document !== undefined) < // your desired code. This is equivalent to a general "try" block > else < // the error code you need to execute when document is undefined. This is equivalent to a general "catch" block >
Code language: JavaScript (javascript)

We will add our code to execute inside the if block. This is so because the document object value comes out to be undefined. Therefore, we can be sure that the error “document is not defined” will not be raised. On the other hand, if the value does come out to be “undefined” for some reason, then we will execute the else block. We use our error code if we need something precisely executed in such a scenario. Otherwise, we can raise an error to alert the user about the issue. I highly recommend you use this structure for error debugging, not only in this specific case but also in a generic setting.

Conclusion

To conclude, I suggest taking preventive measures to be alert to these errors. It can be a real headache to start debugging the error source in an extensive application (personal experience XD). Please do not use any front-end code on your backend system, as it will undoubtedly throw an error. Only declare your tag after the document is ready. Try understanding the client-server model’s basics to appreciate this error’s necessity fully. Also, always use a try-catch or if-else block to catch these errors. Research more about any errors you face and always Google your queries because the internet has an enormous resource for every issue you face. Happy Coding!

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Document: all property

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The Document interface’s read-only all property returns an HTMLAllCollection rooted at the document node. In other words, it returns all of the document’s elements, accessible by order (like an array) and by ID (like a regular object).

Value

An HTMLAllCollection which contains every element in the document.

Special type conversion behavior

For historical reasons, document.all is an object that in many ways behaves like undefined . Specifically:

These special behaviors ensure that code like:

if (document.all)  // Assume that we are in IE; provide special logic > // Assume that we are in a modern browser 

Will continue to provide modern behavior even if the code is run in a browser that implements document.all for compatibility reasons.

However, in all other contexts, document.all remains an object. For example:

• It is not strictly equal to either undefined or null .
• When used on the left-hand side of the nullish coalescing operator ( ?? ) or the optional chaining operator ( ?. ), it will not cause the expression to short-circuit.

Specifications

Browser compatibility

BCD tables only load in the browser

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Document is undefined

Hi all. Before I say any more, I am a compete noob at JavaScript. I have been attempting to learn some though. I want to make some Windows 7/Vista sidebar gadgets, so, as a practise, I am making a very simple calender. It uses a CSS to draw up a background image, which works fine. The manifest is fine, and it installs. I made a javascript to get the date, and I linked it into the base HTML source file. In the javascript, I have a section that uses «document.write()». When I start the gadget, however, I just see the background image and no text. I opened the JavaScript with ‘Microsoft Windows Based Script Host’, which gives me an error saying that ‘document’ is undefined. I tried putting it directly into my HTML source file, but the same result occurs (no text, just the background image). From my understanding, ‘document’ means like the web-page or window (or something!) and doesn’t need to be defined. Can someone point me in the right direction? Here is the script (runs fine until «document.write()»)

var months = new Array(); months[1] = "Jan"; months[2] = "Feb"; months[3] = "Mar"; months[4] = "Apr"; months[5] = "May"; months[6] = "Jun"; months[7] = "Jul"; months[8] = "Aug"; months[9] = "Sep"; months[10] = "Oct"; months[11] = "Nov"; months[12] = "Dec"; var thedate = new Date(); var day = thedate.getDay() + 1; var month = thedate.getMonth() + 1; document.write(day) document.write(month)

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• Latest Post 12 Years Ago Latest Post by hielo

document is an object that exists (is defined) when you are running your javascript from a BROWSER window.

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