如何检查每个数组对象属性是否为空？

Question

function 的目的是在所有answers都为空时得到false 。 目前，当只有一个answers空并且其余的里面有数据时，一些如何得到 **false 。

检查所有answers是否为空的最佳方法是什么。 有些有数据，有些没有，这并不重要。 我只是想看看都是空的还是不空的。

 const questions = [{ "answers": [{ "value": "Browns", "selected": false, }, { "value": "Oranges", "selected": false, }, { "value": "Purples", "selected": false, } ], "info": "", "type": "DESELECT", "lastUpdated": "2021-11-01T22:50:28.359" }, { "answers": [], "info": "", "type": "DESELECT", "lastUpdated": "2021-11-01T22:50:35.392" }, { "answers": [{ "value": "AnimalPrints", "selected": false, }, { "value": "BigLogos", "selected": true, }, { "value": "Floral", "selected": false, } ], "info": "", "type": "DESELECT", "lastUpdated": "2021-11-01T22:50:43.883" } ]; console.clear(); console.log("------------ES6------------"); const es6Result = questions.every((item) => !_.isEmpty(item.answers)); console.log(es6Result); const lodashResult = _.every(questions, !_.isEmpty('answers')); console.log("------------Lodash------------"); console.log(lodashResult);

 <script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js"></script>

Answer 1

你可以使用.some()你会得到true ，如果至少1个answers不为空，你会得到false ，如果所有answers都为空

const es6Result = questions.some((item) => item.answers.length);

Answer 2

我认为您描述的逻辑需要：

const lodashResult = !_.every(questions, _.isEmpty('answers'));

或者

const es6Result = !questions.every((item) => _.isEmpty(item.answers));

Answer 3

 const questions = [{ "answers": [{ "value": "Browns", "selected": false, }, { "value": "Oranges", "selected": false, }, { "value": "Purples", "selected": false, } ], "info": "", "type": "DESELECT", "lastUpdated": "2021-11-01T22:50:28.359" }, { "answers": [], "info": "", "type": "DESELECT", "lastUpdated": "2021-11-01T22:50:35.392" }, { "answers": [{ "value": "AnimalPrints", "selected": false, }, { "value": "BigLogos", "selected": true, }, { "value": "Floral", "selected": false, } ], "info": "", "type": "DESELECT", "lastUpdated": "2021-11-01T22:50:43.883" } ]; console.clear(); console.log("------------ES6------------"); const es6Result = questions.map((item) => _.isEmpty(item.answers)).indexOf(true) > -1; console.log(es6Result);

 <script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js"></script>

Answer 4

这里真的不需要 lodash。 你应该能够通过使用Array.prototype.every来完成你想要的

questions.every((item) => item.answers.length > 0)

只要所有“答案”数组都包含一个或多个项目，这将始终返回 true，否则返回 false。 正如Georgy所说，当您想要检查至少一项时，您可以使用Array.prototype.some 。