javascript “类扩展值 #<Object> 不是构造函数或 null”
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"Class extends value #<Object> is not a constructor or null"
提问by Charlote22
Thanks for reading my post I get this error on my code : "Class extends value # is not a constructor or null" Here is my code, I'm trying to export/import classes.
感谢阅读我的帖子，我的代码出现此错误：“Class extends value # is not a constructor or null”这是我的代码，我正在尝试导出/导入类。
monster.js :
怪物.js：
const miniMonster = require("./minimonster.js");
class monster {
constructor(options = { name }, health) {
this.options = options;
this.health = 100;
this.heal = () => {
return (this.health += 10);
};
}
}
let bigMonster = new monster("Godzilla");
console.log(bigMonster);
console.log(bigMonster.heal());
let mini = new miniMonster("Demon");
console.log(mini);
console.log(mini.heal());
module.exports = monster;
minimonster.js :
小怪物.js :
const monster = require("./monster.js");
class miniMonster extends monster {
constructor(options) {
super(options);
this.health = 50;
this.heal = () => {
return (this.health += 5);
};
}
}
let miniM = new miniMonster("Jon");
console.log(miniM);
module.exports = miniMonster;
Thank you for any help given,
感谢您提供的任何帮助，
Have a good day
祝你有美好的一天
采纳答案by kigiri
I see at least one issue with your requires.
我发现您的需求至少有一个问题。
monster.jsfirst line isconst miniMonster = require("./minimonster.js");minimonster.jsfirst line isconst monster = require("./monster.js");
monster.js第一行是const miniMonster = require("./minimonster.js");minimonster.js第一行是const monster = require("./monster.js");
This is a problem, you can not have both files evaluate at the same time.
I would not require minimonsterfrom monster.js
这是一个问题，您不能同时评估两个文件。我不会要求minimonster从monster.js
This may fix your issue.
这可能会解决您的问题。
回答by Dave Pile
When I get this error message it is because I have done my module.exportswrong.
eg.
当我收到此错误消息时，是因为我module.exports做错了。例如。
publicclass.js
公共类.js
class PublicClass {
.....
}
module.exports.PublicClass = PublicClass;
instead of
代替
module.exports = PublicClass;
回答by lwdthe1
For me, I had introduced a circular dependency.
对我来说，我引入了循环依赖。
回答by Rahul Mogar
I used as per below line.
我按照下面的行使用。
import Base from "./base
and its working fine now
现在它工作正常
