给定以下作为节点树的对象数组
const tree = [
{
label: "Gilfoyle",
data: 160,
children: [],
},
{
label: "Nami",
data: 171,
children: [],
},
{
label: "Root",
data: 172,
expanded: true,
children: [
{
label: "Root child 1",
data: 174,
expanded: true,
children: [
{
label: "Root child 2",
data: 175,
expanded: true,
children: [
{
label: "Root child 3",
data: 176,
expanded: false,
children: [{}],
},
],
},
],
},
],
},
{
label: "sk3wl 0f r00t",
data: 159,
children: [],
},
{
label: "Collection",
data: 166,
children: [],
},
{
label: "Compass",
data: 165,
children: [],
},
{
label: "Sample",
data: 17,
children: [],
},
{
label: "School of root",
data: 18,
children: [],
},
];我需要通过其 id 获取这些对象之一
为此，下面的函数循环遍历每个节点，并将数据属性的 value 与搜索到的节点的 id 进行比较。
function getNode(tree, id) {
if (tree && Array.isArray(tree) && tree.length > 0) {
for (const node of tree) {
if (node.data === id) {
console.dir(node, { depth: null });
return node;
break;
}
getNode(node.children, id);
}
}
}可以在以下代码段中看到该节点。但我需要函数返回节点。
const tree = [
{
label: "Gilfoyle",
data: 160,
children: [],
},
{
label: "Nami",
data: 171,
children: [],
},
{
label: "Root",
data: 172,
expanded: true,
children: [
{
label: "Root child 1",
data: 174,
expanded: true,
children: [
{
label: "Root child 2",
data: 175,
expanded: true,
children: [
{
label: "Root child 3",
data: 176,
expanded: false,
children: [{}],
},
],
},
],
},
],
},
{
label: "sk3wl 0f r00t",
data: 159,
children: [],
},
{
label: "Collection",
data: 166,
children: [],
},
{
label: "Compass",
data: 165,
children: [],
},
{
label: "Sample",
data: 17,
children: [],
},
{
label: "School of root",
data: 18,
children: [],
},
];
function getNode(tree, id) {
if (tree && Array.isArray(tree) && tree.length > 0) {
for (const node of tree) {
if (node.data === id) {
console.dir(node, { depth: null });
return node;
break;
}
getNode(node.children, id);
}
}
}
const output = getNode(tree, 176);
console.dir(output, { depth: null });我已经确认，如果搜索 id 是列表的最后一个元素，它只会返回节点。在其他情况下，如示例所示，代码段返回 undefined
如何在递归函数的循环中返回搜索到的 value？
回答1
一个快速（当然也有点脏）的方法是检查 getNode 是否找到了 value：
const tree = [
{
label: "Gilfoyle",
data: 160,
children: [],
},
{
label: "Nami",
data: 171,
children: [],
},
{
label: "Root",
data: 172,
expanded: true,
children: [
{
label: "Root child 1",
data: 174,
expanded: true,
children: [
{
label: "Root child 2",
data: 175,
expanded: true,
children: [
{
label: "Root child 3",
data: 176,
expanded: false,
children: [{}],
},
],
},
],
},
],
},
{
label: "sk3wl 0f r00t",
data: 159,
children: [],
},
{
label: "Collection",
data: 166,
children: [],
},
{
label: "Compass",
data: 165,
children: [],
},
{
label: "Sample",
data: 17,
children: [],
},
{
label: "School of root",
data: 18,
children: [],
},
];
function getNode(tree, id) {
if (tree && Array.isArray(tree) && tree.length > 0) {
for (const node of tree) {
if (node.data === id) {
console.dir(node, { depth: null });
return node;
break;
}
const found = getNode(node.children, id);
if (found) return found;
}
}
}
const output = getNode(tree, 176);
console.dir(output, { depth: null });