如何检查 JavaScript object 中是否包含值？

Question

0:{date: "2021-1-9", views: 32109, clicks: 279, likes: 4391}
1: {date: "2021-1-10", views: 127568, clicks: 691, likes: 8471}
2: {date: "2021-1-11", views: 17304, clicks: 94, likes: 764}
3: {date: "2021-1-12", views: 11008, clicks: 49, likes: 421}

0: {date: "2021-1-9", views: 32109, clicks: 279}
1: {date: "2021-1-10", views: 127568, clicks: 69}
2: {date: "2021-1-11", views: 17304, clicks: 94}
3: {date: "2021-1-12", views: 11008, clicks: 49}

0: {date: "2021-1-9", views: 32109, likes: 4391}
1: {date: "2021-1-10", views: 127568,likes: 8471}
2: {date: "2021-1-11", views: 17304, likes: 764}
3: {date: "2021-1-12", views: 11008, likes: 421}

我有上面的数据，你可以看到有些没有喜欢，有些没有点击元素，所以我想检查它们是否存在于 arrays 中，并为不存在的特定元素打印为 false在数组中。

Answer 1

Object.prototype.hasOwnProperty()

您可以使用方法hasOwnProperty()检查 object 是否有密钥。

 const obj = [{ date: "2021-1-9", views: 32109, clicks: 279, likes: 4391 }, { date: "2021-1-10", views: 127568, clicks: 691, likes: 8471 }, { date: "2021-1-11", views: 17304, clicks: 94, likes: 764 }, { date: "2021-1-12", views: 11008, clicks: 49, likes: 421 }, { date: "2021-1-9", views: 32109, clicks: 279 }, { date: "2021-1-10", views: 127568, clicks: 69 }, { date: "2021-1-11", views: 17304, clicks: 94 }, { date: "2021-1-12", views: 11008, clicks: 49 }, { date: "2021-1-9", views: 32109, likes: 4391 }, { date: "2021-1-10", views: 127568, likes: 8471 }, { date: "2021-1-11", views: 17304, likes: 764 }, { date: "2021-1-12", views: 11008, likes: 421 } ] let propToLookFor = "likes"; obj.forEach((x) => { if (x.hasOwnProperty(propToLookFor)) { console.log("True"); }else{ console.log("False"); } })