js throw & error All All In One

js throw & error All All In One

throw vs throw Error vs throw new Error

error

Note: Error() can be called with or without new. Both create a new Error instance.

new Error()
new Error(message)
new Error(message, options)
new Error(message, fileName)
new Error(message, fileName, lineNumber)

Error()
Error(message)
Error(message, options)
Error(message, fileName)
Error(message, fileName, lineNumber)

// 關鍵字 new 可以省略
// throw Error 等價於 throw new Error ✅

throw Error('js custom errors ❌!');
// Uncaught Error: js custom errors ❌!

throw new Error('js custom errors ❌!');
// Uncaught Error: js custom errors ❌!

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/Error

try {
  frameworkThatCanThrow();
} catch (err) {
  throw new Error("New error message", { cause: err });
}

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause

throw

throw 'js custom errors ❌!';
// Uncaught js custom errors ❌!

throw new Error('js custom errors ❌!');
// Uncaught Error: js custom errors ❌!

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/throw

try...catch

try {
  do_something();
} catch (err) {
  throw new Error("New error message", { cause: err });
}

try...catch...finally

try {
  tryStatements
} catch (exceptionVar) {
  catchStatements
} finally {
  finallyStatements
}

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/try...catch

demos

throw new Error("Equal")
// Uncaught Error: Equal

throw "Equal"
// Uncaught Equal

https://leetcode.com/problems/to-be-or-not-to-be/submissions/1254538103/?envType=study-plan-v2&envId=30-days-of-javascript

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refs

https://www.cnblogs.com/xgqfrms/p/17187497.html

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