How to use JavaScript Try...Catch statement_Basic knowledge

The purpose of try...catch is to test errors in the code.
Example
try...catch statement
How to write try...catch statement.
try...catch statement with confirmation box
Another example of writing a try...catch statement. JavaScript - Catching Errors
When we surf the Internet, we will always see a Javascript warning box with runtime errors, and we will be asked "Do you want to debug?". Error messages like this may be useful to developers, but not necessarily to users. When errors occur, they often choose to leave the site.
This section explains to you how to capture and handle Javascript error messages so that you can provide more convenience to your audience.
There are two ways to catch errors in a web page:
Use try...catch statement. (Available in IE5, Mozilla 1.0, and Netscape 6)
Use the onerror event. This is the old-fashioned way of catching errors. (Available in versions after Netscape 3)
Try...Catch statement
try...catch can test errors in the code. The try section contains the code that needs to be run, while the catch section contains the code that is run when an error occurs.
Syntax:
try
{
//Run code here
}
catch(err)
{
//Handle errors here
} Note: try...catch uses lowercase letters. Capital letters will go wrong.
Example 1
The following example was originally used to display the "Welcome guest!" message when the user clicks the button. However, alert() in the message() function is mistakenly written as addlert(). At this time the error occurred:

<input type="button" value="View message" onclick="message()">
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We can add try.. .catch statement so that more appropriate action can be taken when an error occurs.
The following example re-modifies the script using try...catch statements. The error occurred because alert() was mistakenly written. But this time, the catch section catches the error and handles it with a prepared piece of code. This code will display a custom error message to inform the user of what happened.

<input type="button" value="View message" onclick="message()">
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Example 2

The next example will be Display a confirmation box that allows the user to choose whether to click the OK button to continue browsing the web page or click the Cancel button to return to the homepage when an error occurs. If the return value of the confirm method is false, the code will redirect the user to another page. If the return value of the confirm method is true, then the code will do nothing. <input type="button" value="View message" onclick="message()">

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