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What will be the output of the following JavaScript Promise code and how does it work?

author
kallyani
easy
0
5
Promise.resolve(1).then(val => {

console.log(val);

return val + 1;

}).then(val => {

console.log(val);

});
Answer
1
2

Explanation

  • Promise.resolve(1) creates a promise that is already resolved with the value 1.
  • The first .then() receives val = 1.
    • It logs 1
    • Returns val + 1, which is 2
  • When a value is returned from .then(), it is automatically wrapped in a resolved promise.
  • The second .then() receives the returned value 2.
    • It logs 2

Key Points

  • Each .then() receives the value returned from the previous .then()
  • Returning a value from .then() passes it to the next .then()
  • Promises allow value chaining

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