javascript - 将某个类的所有元素的ID获取到javascript中的数组中

Question

我读了this question ，并提供了接受的答案:

var ids = $('.cookie').map(function(index) {
    // this callback function will be called once for each matching element
    return this.id; 
});

如何在纯 javascript 中完成上述操作？

Answer 1

我建议如下:

// using Function.prototype.call() to apply 
// Array.prototype.map() to the array-like NodeList returned
// by document.querySelectorAll():
var elementIDs = Array.prototype.map.call(document.querySelectorAll('.cookie'), function (cookie) {
  // the first argument to the anonymous function ('cookie') is
  // the array element of the array over which we're iterating,
  // and is here a DOM node.

  // here, we return the id property of the current node:
  return cookie.id;
});

引用资料:

• > Array.prototype.map() .
• > document.querySelectorAll() .