What,Why,When Use Try-catch in JavaScript

The purpose of try catch blocks to allow you to try to perform and action and then if an exception occurs, catch the exception and deal with it gracefully rather than crashing. A try block is the block of code in which exceptions occur. A catch block catches and handles try block exceptions.

The try statement lets you test a block of code for errors.

The catch statement lets you handle the error.

The throw statement lets you create custom errors.

The finally statement lets you execute code, after try and catch, regardless of the result.

Errors Will Happen!

When executing JavaScript code, different errors can occur.

Errors can be coding errors made by the programmer, errors due to wrong input, and other unforeseeable things.

JavaScript try and catch

The try statement allows you to define a block of code to be tested for errors while it is being executed.

The catch statement allows you to define a block of code to be executed, if an error occurs in the try block.

The JavaScript statements try and catch come in pairs:

try {
Block of code to try
}
catch(err) {
Block of code to handle errors
}

JavaScript Throws Errors

When an error occurs, JavaScript will normally stop and generate an error message.

The technical term for this is: JavaScript will throw an exception (throw an error).

JavaScript will actually create an Error object with two properties: name and message.

The throw Statement

The throw statement allows you to create a custom error.

Technically you can throw an exception (throw an error).

The exception can be a JavaScript String, a Number, a Boolean or an

If you use throw together with try and catch, you can control program flow and generate custom error messages

The finally Statement

The finally statement lets you execute code, after try and catch, regardless of the result:

Syntax

try {
Block of code to try
}
catch(err) {
Block of code to handle errors
}
finally {
Block of code to be executed regardless of the try / catch result
}