declare arrow function in the class

Question

I have created class like below. Is there something wrong with following? I just followed others' way but it continuously gives me, 'Test run failure: file script.js has invalid syntax'. I have searched very hard, I do not think there is any exceptions from them. Could you give some advice for this?

class AAA {
   constructor(value) {
     this.value = value;
   }

   add = a => value + a;
}

You can't have assignments inside the class body. What's wrong with the method syntax: `add(a) { return this.value + a; }`? The arrow function won't work anyway, because you need `this` to access the `value`, which arrow functions can't do. — ibrahim mahrir, Oct 16 '18 at 23:09
Thank you so much for your answers. I just changed into regular function definition. It looked like React component uses that way. :) — Anna Lee, Oct 17 '18 at 19:23

score 0 · Answer 1 · answered Oct 16 '18 at 23:15

You cannot assign in the class body. You can do it in the constructor or you could use TypeScript.

class AAA {
   constructor(value) {
     this.value = value;
     
     this.add = a => this.value + a;
   }
}


let aaa = new AAA(5);

console.log(aaa.add(5));

declare arrow function in the class

1 Answers1