[Solved] What is wrong with this Promise usage in Angular?const p = new Promise((resolve, reject) => { setTimeout(() => resolve('done'), 1000); }); p.then(result => console.log(result)); p.... | Angular

Angular - RxJS and Observables Fundamentals

What is wrong with this Promise usage in Angular?

const p = new Promise((resolve, reject) => {
  setTimeout(() => resolve('done'), 1000);
});
p.then(result => console.log(result));
p.catch(error => console.error(error));
p.cancel();

APromises do not have a cancel() method, so calling it causes an error.

BThe Promise should use reject() instead of resolve() inside setTimeout.

CThe then() method should come after catch(), not before.

DThe Promise constructor is missing the reject parameter.

Step-by-Step Solution

Solution:

Step 1: Check Promise API for cancellation
Promises do not support cancellation; there is no cancel() method.
Step 2: Identify error cause
Calling p.cancel() will cause a runtime error because cancel() is undefined.
Final Answer:
Promises do not have a cancel() method, so calling it causes an error. -> Option A
Quick Check:
Promise cancellation is not supported [OK]

Quick Trick: Promises cannot be cancelled; no cancel() method exists [OK]

Common Mistakes:

MISTAKES

Thinking Promise supports cancel() like Observable
Confusing resolve and reject usage
Believing then() must come after catch()

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More Angular Quizzes

What is wrong with this Promise usage in Angular?

Step 1: Check Promise API for cancellation

Step 2: Identify error cause

Final Answer:

Quick Check:

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