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This article mainly introduces "why javascript does not have permission". In daily operation, I believe that many people have doubts about why javascript does not have permission. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the question of "why javascript does not have authority"! Next, please follow the editor to study!

The reason why javascript does not have permission: 1, due to logic errors, such as closing iframe first, and then calling the function in the main page; 2, because the sub-page is cross-domain, you need to carefully check the src address of iframe.

This article operating environment: windows7 system, javascript1.8.5 version, Dell G3 computer.

Why doesn't javascript have permission?

Javascript has a run-time error: reason for no permissions:

There are two reasons:

1. It's a logic error, such as shutting down iframe and then calling the function in the main page.

two。 The sub-page is cross-domain, so check the src address of iframe carefully.

JavaScript error

The Error object provides information about the error when it occurs.

In the following example, the try statement block contains the undefined function "adddlert". Executing it results in an error, and the catch statement block outputs the error information:

HTML Chinese net JavaScript Error object

In the following example, the try statement block contains the undefined function "adddlert". Executing it results in an error, and the catch statement block outputs the error information.

Try {adddlert ("Welcome guest!");} catch (err) {document.getElementById ("demo") [xss_clean] = err.name + "

"+ err.message;}

Running result:

At this point, the study on "Why javascript does not have permission" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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