Javascript递归，foreach循环不会退出？(Javascript recursion, foreach loop won't exit?)

 我构建了一个简单的Javascript树视图，其中每个节点都有一个名称，一个孩子列表和一个ID： 
 
class Node {
  constructor(name, childNodes, id) {
    this.name = name;
    this.childNodes = childNodes;
    this.id = id;
  }
}
 
 我的目标是创建一个函数“getNodeById（parent，id）”，它返回具有给定ID的节点。 我曾尝试使用递归方法，但在某处必定会出现错误： 
 
function getNodeById(currentNode, id) {
  if (currentNode.id === id) { console.log("found"); return currentNode; }
  currentNode.children.forEach(child => {
    console.log(child);
    return getNodeById(child, id);
  });
}
 
 我的想法是，该函数将搜索childNodes并再次调用自己。 当找到正确的节点时，应该在if语句后返回，然后在foreach循环内返回。 该函数成功找到正确的节点，但不会停止并返回节点。 这是调用getNodeById时的输出（parent，2）; 
 
  
 
 为什么函数在“找到”后退出？ 

I build a simple Javascript treeview, where every Node has a name, a list of children and an ID:
 
class Node {
  constructor(name, childNodes, id) {
    this.name = name;
    this.childNodes = childNodes;
    this.id = id;
  }
}
 
My Aim is to create a function "getNodeById(parent, id)", that returns the Node with the given ID. I have tried using a recursive method, but there has to be a mistake somewhere:
 
function getNodeById(currentNode, id) {
  if (currentNode.id === id) { console.log("found"); return currentNode; }
  currentNode.children.forEach(child => {
    console.log(child);
    return getNodeById(child, id);
  });
}
 
My idea is, that the function will search through the childNodes and call itsself again. When the the correct node is found, it should be returned after the if-statement, then inside the foreach loop. The function finds the right node successfully but it won't stop and return the Node. Here is the output when calling getNodeById(parent, 2);
 
 
Why doesn't the function exit after the "found"?

原文：https://stackoverflow.com/questions/50025579