Typescript class 方法返回未定义

Question

I have created a typescript class, and i have two functions inside it, which are supposed to compute the ratio of likes and dislikes.

    export class MyClass {
        thumbedUp?: number;
        thumbedDown?: number;
    
        likePercent?= () => Math.round((this.thumbedUp / (this.thumbedDown + this.thumbedUp)) * 100);
        dislikePercent?= () => Math.round((this.thumbedDown / (this.thumbedDown + this.thumbedUp)) * 100);

}

but when i create a MyClass instance like myClass:MyClass = {thumbedUp: 10, thumbedDown: 12}; and i try to call myClass.likePercent, it returns undefined. I really don't understand why as my object is instanciated... Can you help me?

Thanks

Answer 1

export class MyClass {
        thumbedUp: number;
        thumbedDown: number;
  constructor(thumbedUp:number, thumbedDown:number ){
      this.thumbedDown=thumbedUp;
      this.thumbedUp=thumbedDown;
  }

 likePercent():number{

return Math.round((this.thumbedUp / (this.thumbedDown + this.thumbedUp)) * 100);;
 }
    
dislikePercent():number{
return Math.round((this.thumbedDown / (this.thumbedDown + this.thumbedUp)) * 100);
}
}
 



var myclass = new MyClass(10,12);
console.log(myclass.likePercent())

Answer 2

do like me

 export class MyClass {
        thumbedUp: number;
        thumbedDown: number;
  constructor(){
      this.thumbedDown=0;
      this.thumbedUp=0;
  }

 likePercent():number{

return Math.round((this.thumbedUp / (this.thumbedDown + this.thumbedUp)) * 100);;
 }
    
dislikePercent():number{
return Math.round((this.thumbedDown / (this.thumbedDown + this.thumbedUp)) * 100);
}
     
    

}