在JS中具有多個參數的函數中訪問對象范圍

Question

我得到了這個功能：

 const debounce = (func, delay) => { let inDebounce; return function() { const context = this const args = arguments clearTimeout(inDebounce) inDebounce = setTimeout(() => func.apply(context, args), delay) } } var likes_btn = document.getElementsByClassName("js-submit-like"); for (var i = 0; i < likes_btn.length; i++) { likes_btn[i].addEventListener('click', debounce(function(el) { alert("hello"); el.preventDefault(); }, 500)); } 

所以事情是，在執行反跳操作之前，我需要使用.preventDefault() 。 當前，真正發生的是在debounce()的末尾執行，而不是在函數范圍內執行。

如何進入功能范圍？ 謝謝！

Answer 1

只需將其移到debouncer回調之外即可：

const debouncer = debounce(() => alert("hello"), 500);
likes_btn[i].addEventListener('click', function(event) {
   event.preventDefault();
   debouncer(event);
});

使用一些鏈接函數可能會更優雅：

 const both = (fn1, fn2) => (...args) => (fn1(...args), fn2(...args));
 const stop = event => event.preventDefault();
 const listen = (el, name, handler) => el.addEventListener(name, handler);

 for(const btn of likes_btn) {
   listen(btn, "click", both(
    debounce(() => alert("hello"), 500),
    stop
   ));
}

Answer 2

創建一個單獨的debouncer回調，偵聽器可以關閉該回調：

 const debounce = (func, delay) => { let inDebounce; return function() { const context = this const args = arguments clearTimeout(inDebounce) inDebounce = setTimeout(() => func.apply(context, args), delay) } } var likes_btn = document.getElementsByClassName("js-submit-like"); for (let i = 0; i < likes_btn.length; i++) { const button = likes_btn[i]; const debouncer = debounce((e) => console.log("Hello", button), 500); // you can also use e.target to refer to the button button.addEventListener('click', function(e) { console.log("clicked"); debouncer(e); e.preventDefault(); }); } 

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