Constructor overload in TypeScript

Question

Has anybody done constructor overloading in TypeScript. On page 64 of the language specification (v 0.8), there are statements describing constructor overloads, but there wa

Answer 1

TypeScript allows you to declare overloads but you can only have one implementation and that implementation must have a signature that is compatible with all overloads. In your example, this can easily be done with an optional parameter as in,

interface IBox {    
    x : number;
    y : number;
    height : number;
    width : number;
}

class Box {
    public x: number;
    public y: number;
    public height: number;
    public width: number;

    constructor(obj?: IBox) {    
        this.x = obj && obj.x || 0
        this.y = obj && obj.y || 0
        this.height = obj && obj.height || 0
        this.width = obj && obj.width || 0;
    }   
}

or two overloads with a more general constructor as in,

interface IBox {    
    x : number;
    y : number;
    height : number;
    width : number;
}

class Box {
    public x: number;
    public y: number;
    public height: number;
    public width: number;

    constructor();
    constructor(obj: IBox); 
    constructor(obj?: any) {    
        this.x = obj && obj.x || 0
        this.y = obj && obj.y || 0
        this.height = obj && obj.height || 0
        this.width = obj && obj.width || 0;
    }   
}