TypeScript 4.0
Class Property Inference from Constructors
TypeScript 4.0 can now use control flow analysis to determine the types of properties in classes when noImplicitAny is enabled.
class Square {
// Previously: implicit any!
// Now: inferred to `number`!
area;
sideLength;
constructor(sideLength: number) {
this.sideLength = sideLength;
this.area = sideLength ** 2;
}
}