Introduction to Errors in JavaScript

JavaScript From Beginner To Advanced

0% completed

Errors in JavaScript are disruptions in the normal flow of a program's execution, typically occurring when the JavaScript engine encounters scenarios it cannot handle. Understanding error handling is crucial for writing robust JavaScript applications that can gracefully handle unexpected situations without crashing.

Types of Errors

Syntax Errors: Occur during parsing when the JavaScript engine encounters code that does not conform to the syntax rules of the language. For example, missing a bracket or misusing reserved keywords.
Runtime Errors: Occur during execution, after the code has passed parsing. These are also known as exceptions and can be caused by various reasons such as trying to call a function that doesn't exist, accessing a variable that is not defined, or executing a division by zero.
Logical Errors: These do not throw errors in the traditional sense because the code executes successfully from a syntax and runtime perspective, but the results are not as intended by the developer.

Common JavaScript Error Objects

JavaScript has several built-in error constructors that represent errors in specific contexts:

Error Type	Description
`Error`	The generic error constructor for creating a generic error.
`TypeError`	Indicates an operation was performed on the wrong type.
`SyntaxError`	Represents an error in the syntax of the code.
`RangeError`	Indicates a value was not in the set or range of allowed values.
`ReferenceError`	Thrown when trying to reference a variable that is not declared.
`URIError`	Occurs when global URI handling functions are misused.

This introduction provides a foundational understanding of error handling in JavaScript. In the next sections, we'll explore specific error handling patterns and mechanisms, such as the try...catch statement and creating custom error types to better manage specific error scenarios in your applications.

.....

Like the course? Get enrolled and start learning!