In the Promise chain, if a then method returns not a Promise object, but an ordinary value (such as a number), then the next thenThe method will continue to execute with this value as parameter. This value will be wrapped into a resolved Promise and then passed to the nextthen method. In this case, the Promise chain will still maintain the normal execution flow, even if a Promise is not returned.
Here is a simple example that demonstrates this situation:
const promise = new Promise((resolve, reject) => {
resolve(42); // Resolving with a number
});
promise.then(value => {
console.log(value); // Output: 42
return 100; // Returning a number, not a Promise
}).then(newValue => {
console.log(newValue); // Output: 100
});
In this example, the firstthen method returns a number 100 instead of a Promise object. The next then method will still be executed normally and use the number returned by the previous then method as a parameter.
It should be noted that even if a Promise is not returned, the execution sequence of the then method is still asynchronous, because the characteristics of Promise ensure asynchronous execution.