Learn TypeScript 3 by Building Web Applications

Creating the TodoItem class

Remove everything from the todo-it.ts file. Then, add the definition of the TodoItem class:

class TodoItem { 
    private readonly _creationTimestamp: number;    private readonly _identifier: string; 

    constructor(private _description: string, identifier?: string) { 
        this._creationTimestamp = new Date().getTime();  

        if (identifier) { 
            this._identifier = identifier; 
        } else { 
            // this is just for the example; for any real project, use 
            // UUIDs instead: https://www.npmjs.com/package/uuid 
            this._identifier = Math.random().toString(36).substr(2,  9); } } get creationTimestamp(): number { return this._creationTimestamp; } get identifier(): string { return this._identifier; } get description(): string { return this._description; } } ...