Question

所以我正在尝试编写一些代码来检查两个人是否共享同一个生日。你可以看到人“a”和人“b”不共享同一个生日，但控制台上的输出是：

a was born on day 1
a has the same birthday as a
a has the same birthday as b
b was born on day 2
b has the same birthday as a
b has the same birthday as b

虽然它应该是：

a was born on day 1
a has the same birthday as a
b was born on day 2
b has the same birthday as b

代码：

var people = {
    a: {
        name: "a",
        birthday: 1,
    },
    b: {
        name: "b",
        birthday: 2,
    }
};


for(var x in people) {
    console.log(people[x].name + " was born on day " + people[x].birthday)
    for(var y in people) {
        if(people[x].birthday = people[y].birthday) {
            console.log(people[x].name + " has the same birthday as " + people[y].name)
        }
    }
}

people[x].birthday = people[y].birthday

似乎是问题的根源。

Answer 1

people[x].birthday == people[y].birthday

您需要==而不是=。 =是作业，==是比较

使用=，您将people[y].birthday值分配给people[x].birthday值，然后两个生日相同。

使用==，您将比较y是否与x生日相同

Answer 2

您只需要使用Identity / strict相等运算符===来比较JavaScript中的两个对象，这样就可以：

people[x].birthday === people[y].birthday

查看 Comparison operators 。

注意：

people[x].birthday = people[y].birthday始终为true，因为您正在执行作业。

Answer 3

您可以使用===。这意味着：等值和相等的类型

详情请见：http://www.w3schools.com/js/js_comparisons.asp

此致

Answer 4

这里有两个问题：

您的比较看起来像是作业而不是相等检查

people[x].birthday === people[y].birthday

应该是：

for(var index = 0; index < people.length; index++) {
   console.log(people[x].name + " was born on day " + people[x].birthday)
    for(var inner = index; inner < people.length; inner+1) {
        if(people[index].birthday == people[inner].birthday) {
            console.log(people[index].name + " has the same birthday as " + people[inner].name)
        }
    }
}

第二个是你的for循环。从同一索引（0）开始循环遍历集合两次。

最简单的方法是将当前人与列表中的每个人进行比较

QGraphicsEllipseItem

比较同一对象中的值

4 个答案: