How to throw an error in JavaScript
Łukasz Holeczek
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Throwing errors is essential for handling invalid states and exceptional situations in JavaScript applications effectively.
As the creator of CoreUI with over 25 years of development experience, I’ve built robust error handling into countless production systems.
The most effective solution is to use the throw statement with an Error object, providing clear error messages.
This approach makes debugging easier and allows proper error handling with try-catch blocks.
Use the throw statement with an Error object to throw custom errors.
function divide(a, b) {
if (b === 0) {
throw new Error('Division by zero is not allowed')
}
return a / b
}
try {
const result = divide(10, 0)
} catch (error) {
console.error('Error:', error.message)
}
The throw statement stops execution and passes control to the nearest catch block. Creating a new Error() with a descriptive message provides context about what went wrong. The Error object includes a stack trace that helps identify where the error originated. You can also throw specific error types like TypeError, RangeError, or create custom error classes for more granular error handling.
Best Practice Note
This is the same error handling pattern we use in CoreUI to ensure components fail gracefully with clear feedback. Always provide meaningful error messages that explain what went wrong and potentially how to fix it, making debugging and maintenance significantly easier for your team.
