Typescript: this.property inside a function gives error of type implicitly any. Can't call new-CodePudding

I'm trying to integrate typescript into my learning path and understanding the differences with javascript.

So far I was able to resolve all issues but I got stuck on something that appears pretty basic.

function Person() {
    // ERROR: this implicitly has type any because it does not have a type annotation
    this.name = 'brad';
}

// ERROR: new expression, whose target lacks a construct signature, implicitly has an any type
const brad = new Person();

console.log( brad );

I tried some possible solutions:

disabled no implicit this in tsconfig:

this would work in removing the first error, but the one on the new Person() remains

set this: any in the parameter parenthesis (with noimplicitthis to true)

function Person( this: any ) { // ERROR: unexpected any. specify a different type

tried to use an arrow function to store it
tried using constructor inside the Person function

Had a look at the official typescript handbook but I just don't seem to find anything that correlates with my current problem.

Why does the above code work in JS while in typescript I can't seem to make it work?

CodePudding user response：

Typescript is complaining here that it doesn't know at declaration what is the type of this and what it should return

We can solve this in 2 ways -

Solution 1: (Preferred)

// Convert this constructor function to Person

class Person {
    name = 'brad'
}

const brad = new Person();

console.log( brad );

Solution 2: (Hacky)

interface Person1 {
    name: string
    // All properties of Person goes here
}

const  Person1 = function (this: Person1){
    this.name = 'brad'
} as any as { new (): Person1 }

const foo = new Person1();

console.log(foo);

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