How an Anti-TypeScript “JavaScript developer” like me became a TypeScript fan(chiragswadia.medium.com)

    type Thing = {
        name: string,
    };

    function getThing(): Thing {
        return JSON.parse('{"error": "invalid id"}')
    }

    const thing: Thing = getThing(); // lie to me!
    console.log(thing.name);

  let myColor: Color | undefined;

    function foo(arr: number[]) {
        const m: number = arr[3]; // typechecks
        if (m === undefined) {
            // this IS reachable
            console.log("arr does not contain key `[3]`");
        }
    }

    let a = [];
    a[5] = "five";
    console.log(a.length); // 6
    console.log(a[4]); // undefined (!)