Question

所以我正在关注codecademy的javascript课程，我决定在我自己的脚本上尝试一下。所以脚本是：

function family1 (name, age) {
    this.name = name;
    this.age = age;
}

var family = new Array();

family[0] = new family1("alice", 40);
family[1] = new family1("bob", 42);
family[2] = new family1("michelle", 8);
family[3] = new family1("timmy", 8);

printFamily1 = function(person) {
        console.log(person.name + " aged " + person.age);
}

console.log(printFamily1(family[0]))
console.log(printFamily1(family[1]))
console.log(printFamily1(family[2]))
console.log(printFamily1(family[3]))

它有效，但在控制台中，它打印

alice aged 40
undefined
bob aged 42
undefined
michelle aged 8
undefined
timmy aged 8
undefined

它有效，但我不想要未定义的部分！我该如何解决这些问题！

Answer 1

将printFamily1函数更新为：

printFamily1 = function(person) {
        console.log(person.name + " aged " + person.age); 
        return (person.name + " aged " + person.age);
}

问题是您尝试打印printFamily1返回的内容，但您没有定义返回值。因此，只需在控制台中添加要打印的内容

Answer 2

您有两个选择：

请勿再次致电{"epn":{"events":[{"name":"STCSensor","createdDate":"Mon Oct 12 2015","attributes":[ {"name":"entityType","type":"String","dimension":0}, {"name":"Serial","type":"Double","dimension":0}, {"name":"BatteryLevel","type":"Integer","dimension":0}, {"name":"CurrentRSSI","type":"Integer","dimension":0}, {"name":"LastPacketRSSI","type":"Integer","dimension":0}, {"name":"LastPacketSNR","type":"Integer","dimension":0}, {"name":"timestamp","type":"Integer","dimension":0}, {"name":"timestampDelta","type":"Integer","dimension":0}, {"name":"timestampDelta2","type":"Integer","dimension":0}, {"name":"Latitude","type":"Double","dimension":0}, {"name":"Longitude","type":"Double","dimension":0}, {"name":"Altitude","type":"Integer","dimension":0}, {"name":"Speed","type":"Integer","dimension":0}, {"name":"LatitudeDelta1","type":"Integer","dimension":0}, {"name":"LongitudeDelta1","type":"Integer","dimension":0}, {"name":"AltitudeDelta1","type":"Integer","dimension":0}, {"name":"SpeedDelta1","type":"Integer","dimension":0}, {"name":"LatitudeDelta2","type":"Integer","dimension":0}, {"name":"LongitudeDelta2","type":"Integer","dimension":0}, {"name":"AltitudeDelta2","type":"Integer","dimension":0}, {"name":"SpeedDelta2","type":"Integer","dimension":0}, {"name":"temperature","type":"Integer","dimension":0}, {"name":"pressure","type":"Integer","dimension":0}, {"name":"humidity","type":"Integer","dimension":0}, {"name":"temperatureCal","type":"Double","dimension":0}, {"name":"pressureCal","type":"Double","dimension":0}, {"name":"humidityCal","type":"Double","dimension":0}, {"name":"CO","type":"Integer","dimension":0}, {"name":"NO","type":"Integer","dimension":0}, {"name":"NO2","type":"Integer","dimension":0}, {"name":"Ozone","type":"Integer","dimension":0}, {"name":"COCal","type":"Double","dimension":0}, {"name":"NOCal","type":"Double","dimension":0}, {"name":"NO2Cal","type":"Double","dimension":0}, {"name":"OzoneCal","type":"Double","dimension":0}, {"name":"entityId","type":"Integer","dimension":"0"}]},：
```
console.log
```
请勿在函数
中调用printFamily1(family[0]) printFamily1(family[1]) printFamily1(family[2]) printFamily1(family[3])
```
console.log
```

Javascript一直说未定义

2 个答案: