4.JS exception handling and event handling

Abnormal:

1. Exception: When the JS engine executes the JS code, an error occurs, causing the program to stop running.

2. Exception thrown: When an exception is generated and an error message is generated for this exception.

3. Exception Capture:

try{

The code block in which the exception occurred;

}catch (Err) {

Error handling information;

}

4.Throw statement:

Create a custom error by using the throw statement;

Usually throw is used in conjunction with try{}catch{}.

Write an example:

Function Demo () {

try{

var e=10;

if (e==10) {

Throw "Not equal to 10 ah";

}catch (Err) {

alert (err);//The output here is not equal to 10.

}

Event:

Event:

4.JS exception handling and event handling