有没有比JavaScript中的setTimeout更好的东西？

Question

In the code below I have had to introduce setTimeOut() to stop the second function running before the first function has completely finished (see towards the bottom of filterMovies() ). Before that, I was trying to use both a final-iteration-only call callback (in my case the same code minus the setTimeOut() and duration) but it would still run before the first code had fully executed.

I presume this is because I'm dealing with a couple of hundred $(".movie") elements (although I don't really know).

setTimeOut() works okay but it seems inelegant, both in terms of coding and performance on the page (the text updates after a delay). In the spirit of better coding practice, is there a more efficient way of saying "hey, updateSearchInfo , don't even think about running until after that very last element has either slid up or slid down?

function filterMovies() {
  $(".movie").each(function(i) {
    var movie = $(this);

    var genreMatch = 
      !chosenGenres.length 
        ? true 
        : chosenGenres.every(elem => movie.find(".genre").text().indexOf(elem) !== -1);

    var directorMatch = 
      !chosenDirectors.length 
        ? true 
        : chosenDirectors.every(elem => movie.find(".director").text().indexOf(elem) !== -1);

    var countryMatch = 
      !chosenCountries.length 
        ? true 
        : chosenCountries.every(elem => movie.find(".countries").text().indexOf(elem) !== -1);

    i === $(".movie").length -1 
      ? genreMatch && directorMatch && countryMatch 
        ? movie.slideDown(setTimeout(function() {updateSearchInfo()}, 1000)) 
        : movie.slideUp(setTimeout(function() {updateSearchInfo()}, 1000))
      : genreMatch && directorMatch && countryMatch 
        ? movie.slideDown() 
        : movie.slideUp();
  });
}

function updateSearchInfo() {
    movieCount = $(".movie:visible").length;
    $("#search-info").text("Showing " + movieCount + " movies.");
}

Thanks in advance!

Answer 1

jQuery's slide* functions take a callback parameter that runs on completion:

complete Type: Function() A function to call once the animation is complete, called once per matched element.

...
movie.slideDown(updateSearchInfo);
...