如何修复对象"undefined"

Question

请告诉我如何解决，答案带有"对象未定义"。

var dog = {
name : "Fido",
weight : 20.2,
age : 4,
breed : "mixed",
activity : "fetch balls"
};
var bark;
if (dog.weight > 20) {
bark = "WOOF WOOF";
} else {
bark = "woof woof";
}
var speak = dog.name + " says " + dog.bark + " when he wants to " +     dog.activity;
console.log(speak);

Answer 1

如果要将其设置为dog对象的属性，bark = "..."请将其设置为：

dog.bark = "WOOF WOOF";

var dog = {
name: "Fido",
weight: 20.2,
age: 4,
breed: "mixed",
activity: "fetch balls"
};
if (dog.weight > 20) {
dog.bark = "WOOF WOOF";
} else {
dog.bark = "woof woof";
}
var speak = dog.name + " says " + dog.bark + " when he wants to " + dog.activity;
console.log(speak);