按值在深層嵌套 object 中查找 object

Question

我想按值在深層嵌套的 object 中找到一個 object id 。 我嘗試用遞歸來做到這一點，但無法弄清楚為什么會出現“未定義”。

在這段代碼中，我在控制台"final result: 234324234"是正確的，但由於某種原因，這個結果沒有從這個 function 返回。

請看一下。

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

您不會返回遞歸時獲得的值。 嘗試這個：

 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

您忘記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

您需要在遞歸調用之前添加“return”

return findContractStage(obj.children);

和

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

因此，您的遞歸 function 會盡可能深入並返回您的 id 值。