Trying to play with how promises and async code works by making a calculator that will give me the answer after the given ms.
const timeout = ms => new Promise(resolve => setTimeout(resolve, ms));
const add = (number1, number2) => {
return new Promise(resolve => {
timeout(1000).then(resolve(number1 + number2));
});
};
add(5,3).then(result => console.log(result))
Why isn’t the add function waiting for the timeout? It goes directly to resolve regardless of how many ms I pass in. Omitted reject to make it more clear.
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Answer
You call resolve immediately:
const add = (number1, number2) => {
return new Promise(resolve => {
timeout(1000).then(() => {
resolve(number1 + number2);
});
});
};
As timeout is a Promise you can remove your outer completely:
const add = (number1, number2) => {
return timeout(1000).then(() => {
return number1 + number2;
});
};