问题
I have a code like that:
var originalFunction = function() {
return 'some value';
};
var debouncedFunction = _.debounce(originalFunction, 3000);
console.log('debouncedFunction() result: ', debouncedFunction());
console.log('originalFunction() result: ', originalFunction());
(codepen link)
And the result in the console is:
debouncedFunction() result: undefined
originalFunction() result: some value
As you can see, the debounced function doesn't return anything. I understand that it's caused by an internal timer in the debounced function, but is there away around that?
回答1:
that's because debounced functions are called asynchronously - you can't return a value from them, although you can call another function passing the result:
var originalFunction = function() {
console.log('some value');
// or something like: callback(result)
};
var debouncedFunction = _.debounce(originalFunction, 3000);
console.log('debouncedFunction() result: ', debouncedFunction());
回答2:
under the hood _.debounce uses setTimout, you need a callback to return value from a async function.
function originalFunction (callback) {
callback("some value");
}
Here is a great link on the same, https://john-dugan.com/javascript-debounce/
来源：https://stackoverflow.com/questions/37836660/how-to-return-value-from-debounced-function-in-javascript