javascript - 当你通过引用传递时，我们会改变状态吗

Question

我有以下功能:

filterList(event) {
  var updateList = this.state.initialItems;

  updateList = updateList.filter(function(item) {
                  return item.search(event.target.value) !== -1;
               });

  this.setState({currentItems: updateList });
}

如果我们通过引用传递，updateList 和 this.state.initialItems 不是指向同一件事吗？

如何复制 this.state.initialItems？

Answer 1

If we are passing by reference isn't updateList and this.state.initialItems pointing to the same thing?

没有。您将返回一个全新的数组(根据 MDN ):

The filter() method creates a new array with all elements that pass the test implemented by the provided function.