Typescripting a method separated from an object

[marsh fog]

Hi how do I go about resolving the TS errors in below code?
I've bolded with ****** the ones that throw errors and complaining that they have implicitly any type

  function Pet(type: any, legs: any) {
    **this**.type = type;
    **this**.legs = legs;
  
    **this**.logInfo = function() {
      console.log(this === myCat); // => true
      console.log(`The ${this.type} has ${this.legs} legs`);
    };
  }
  
  const myCat = **new Pet('Cat', 4)**;
  
  // Create a bound function
  const boundLogInfo = myCat.logInfo.bind(myCat);
  // logs "The Cat has 4 legs"
  setTimeout(boundLogInfo, 1000);

[late onyx]

you can't put formatting inside a codeblock (except md, kinda) fyi

anyways you haven't told ts that Pet is a constructor function

im not sure you can

why not just use a class?

[marsh fog]

Interesting, so some format may no longer work when translating to TS

I'm still kinda noob in JS so not sure how to turn it into a class

or vice versa

[marsh fog]

I think I managed to convert it to a class but it still complains in several areas.

  class Pet {
    constructor(type: any, legs: any){
        this.type = type;
        this.legs = legs;
    }

    this.logInfo = function() {
        console.log(this === myCat); // => true
        console.log(`The ${this.type} has ${this.legs} legs`);
    };
  }

[junior comet]

Constructor functions are the old old way of doing classes back when JS didn't have dedicated class syntax, it shouldn't be used nowadays.

Based on best guesses, you probably want something like:

class Pet {
    type: string
    legs: number

    constructor(type: string, legs: number) {
        this.type = type
        this.legs = legs
    }

    logInfo() {
        console.log(...)
    }
}

There's also a shorthand for doing constructors + parameters + properties:

class Pet {
    constructor(
        public type: string,
        public legs: number,
    ) {}
}

Although I personally don't like it.

[marsh fog]

Yea I prefer more straightforward syntax like your first one

Thank you Chris and Burrito