按值在深层嵌套 object 中查找 object

Question

我想按值在深层嵌套的 object 中找到一个 object id 。 我尝试用递归来做到这一点，但无法弄清楚为什么会出现“未定义”。

在这段代码中，我在控制台"final result: 234324234"是正确的，但由于某种原因，这个结果没有从这个 function 返回。

请看一下。

jsbin 中的演示

 let obj = { "uuid": "344444", "entityName": "priceFormationPhase", "id": 2, "value": "foo", "children": { "4": { "uuid": "44444", "entityName": "organization", "id": 4, "value": "ffffff", "children": { "344534": { "uuid": "33333", "entityName": "contract", "id": 928688, "value": "dh", "children": { "345345": { "uuid": "222222222", "entityName": "contractPhase", "id": 234324234, "value": "111", "children": {} } } } } } } }; function findContractStage(obj) { if ((typeof obj.children === 'object') && (Object.keys(obj.children).length > 0)) { findContractStage(obj.children); } else if (typeof obj[Object.keys(obj)[0]] === 'object') { findContractStage(obj[Object.keys(obj)[0]]); } else if (obj.entityName) { console.log(`final result: ${obj.id}`); return obj.id; } } let contractStageId = findContractStage(obj); console.log(`contractStageId: ${contractStageId}`);

Answer 1

您不会返回递归时获得的值。 尝试这个：

 let obj = { "uuid": "344444", "entityName": "priceFormationPhase", "id": 2, "value": "foo", "children": { "4": { "uuid": "44444", "entityName": "organization", "id": 4, "value": "ffffff", "children": { "344534": { "uuid": "33333", "entityName": "contract", "id": 928688, "value": "dh", "children": { "345345": { "uuid": "222222222", "entityName": "contractPhase", "id": 234324234, "value": "111", "children": {} } } } } } } }; function findContractStage(obj) { if ((typeof obj.children === 'object') && (Object.keys(obj.children).length > 0)) { return findContractStage(obj.children); } else if (typeof obj[Object.keys(obj)[0]] === 'object') { return findContractStage(obj[Object.keys(obj)[0]]); } else if (obj.entityName) { console.log(`final result: ${obj.id}`); return obj.id; } } let contractStageId = findContractStage(obj); console.log(`contractStageId: ${contractStageId}`);

Answer 2

您忘记return function

 let obj = { "uuid": "344444", "entityName": "priceFormationPhase", "id": 2, "value": "foo", "children": { "4": { "uuid": "44444", "entityName": "organization", "id": 4, "value": "ffffff", "children": { "344534": { "uuid": "33333", "entityName": "contract", "id": 928688, "value": "dh", "children": { "345345": { "uuid": "222222222", "entityName": "contractPhase", "id": 234324234, "value": "111", "children": {} } } } } } } }; function findContractStage(obj) { if ((typeof obj.children === 'object') && (Object.keys(obj.children).length > 0)) { return findContractStage(obj.children); } else if (typeof obj[Object.keys(obj)[0]] === 'object') { return findContractStage(obj[Object.keys(obj)[0]]); } else if (obj.entityName) { console.log(`final result: ${obj.id}`); return obj.id; } } let contractStageId = findContractStage(obj); console.log(`contractStageId: ${contractStageId}`);

Answer 3

您需要在递归调用之前添加“return”

return findContractStage(obj.children);

和

return findContractStage(obj[Object.keys(obj)[0]]);

因此，您的递归 function 会尽可能深入并返回您的 id 值。