javascript - 通过 UID 定位对象的递归 JavaScript 函数

Question

我在返回在此层次树中找到的元素时遇到问题。例如，如果我选择的项目是:

{
 "UID": 49,
 "GUID": "",
 "LocationName": "Doctor Smith's Office",

 "LocationType": {
    "UID": 2,
    "LocationTypeName": "Practice",
    "Description": "other location"
 }
}

我会将 UID 与下面的对象数组进行匹配。

{
  UID: 2,
  GUID: "",
  LocationName: "USA",
  ParentLocation: null,
  subs: [{
	UID: 42,
	GUID: "",
	LocationName: "New Jersey",
	Description: "",
	subs: [{
		UID: 3,
		GUID: "",
		LocationName: "Essex County",
		ParentLocation: null,
		"subs":[
			UID: 4,
			LocationName: "Newark",
			ParentLocation: 3,
			"subs": [
				{
					"UID": 49,
					"GUID": "",
					"LocationName": "Doctor Smith's Office",
													
					"LocationType": {
						"UID": 2,
						"LocationTypeName": "Practice",
						"Description": "other location"
					},                                    
					"subs": [
						{
							"HostID": 38,
							"HostName": "Ocean Host",
						}
					]
				}
			]
		]
	  }                  
	]
  }]
};

let foundItem = this.findInTreeView(this.treeviewData[0], node.selectedNode);

// find selected node in treeview nav
	// param: data - the treeview dataset
	// param: selected - the selected node to be searched for in param 'data'
	findInTreeView(data: any, selected: any )	{		
		let found;
		if (this.foundInTree(data, selected)) {			
			return data;
		}
		let elem;
		let ary = data.subs;
		for (var i=0; i < ary.length; i++) {
			elem = ary[i];
			if (this.foundInTree(elem, selected)) {		
                // *** PROBLEM: If func has return true, I want to return the 'elem' object.	
				return elem;
			}
		}
		for (var i=0; i < ary.length; i++) {
			elem = ary[i];
			if (elem.subs !== undefined) { 
				// recurse subs array
				let found = this.findInTreeView(elem, selected); 
				if (found) {
					return elem;
				}
			}
		}	
		//return elem;		
	}
  
  foundInTree(treeItem, node) {
		if (treeItem.UID === node.UID) {
			return true;			
		}
		else {
			return false;
		}
	}

Answer 1

使用递归reduce函数会容易得多，如下所示:

const input={UID:2,GUID:"",LocationName:"USA",ParentLocation:null,subs:[{UID:42,GUID:"",LocationName:"New Jersey",Description:"",subs:[{UID:3,GUID:"",LocationName:"Essex County",ParentLocation:null,"subs":[{UID:4,LocationName:"Newark",ParentLocation:3,"subs":[{"UID":49,"GUID":"","LocationName":"Doctor Smith's Office","LocationType":{"UID":2,"LocationTypeName":"Practice","Description":"other location"},"subs":[{"HostID":38,"HostName":"Ocean Host",}]}]}]}]}]};

const findUIDObj = (uid, parent) => {
  const { UID, subs } = parent;
  if (UID === uid) {
    const { subs, ...rest } = parent;
    return rest;
  }
  if (subs) return subs.reduce((found, child) => found || findUIDObj(uid, child), null);
};
console.log(findUIDObj(49, input))