Error Handling

Practical ~15 min read

The try...catch Statement

The try statement defines a code block to run (to try).

The catch statement defines a code block to handle any error.

The finally statement defines a code block to run regardless of the result.

HTML

CSS

<h2>Try/Catch Demo</h2>
<p id='tryOutput'></p>

The throw Statement

The throw statement allows you to create a custom error.

HTML

CSS

<h2>Throw Demo</h2>
<input id='demo' type='text' placeholder='Enter a number between 5 and 10'>
<button onclick='myFunction()'>Test Input</button>
<p id='throwOutput'></p>

The finally Statement

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

HTML

CSS

<h2>Finally Demo</h2>
<p id='finallyOutput'></p>

Summary

Use try...catch to handle runtime errors gracefully.
Use throw to create custom errors.
Use finally to execute code regardless of the outcome (e.g., cleanup).

Quick Quiz

Which block is executed regardless of the result?

try

catch

finally

throw

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The try...catch Statement

The throw Statement

The finally Statement

Summary

Quick Quiz

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