var a = 10;

function f() {
  var message = "Hello, world!";

  return message;
}

function f() {
  var a = 10;
  return function g() {
    var b = a + 1;
    return b;
  }
}

var g = f();
g();

function f(suoldInitialize: boolean) {
  if (shouldInitialize) {
    var x = 10;
  }

  return x;
}

f(true);  // return 10
f(false);  // return undefined

for (var i = 0; i < 10; i++) {
  setTimeout(function() { console.log(i); }, 100 * i);
}

for (var i = 0; i < 10; i++) {
  (function(i) {
    setTimeout(function() { console.log(i); }, 100 * i );
  })(i);
}

function f(input: boolean) {
  let a = 100;

  if (input) {
    let b = a + 1;
    return b;
  }

  return b; // error!
}

console.log(bar);
let bar;

function f(condition, x) {
  if (condition) {
    let x = 100;
    return x;
  }

  return x;
}

f(false, 0);
f(true, 0);

function sumMatrix(matrix: number[][]) {
  let sum = 0;
  for (let i = 0; i <matrix.legnth; i++) {
    var currentRow = matrix[i];
    for (let i = 0; i< currentRow.length; i++) {
      sum += currentRow[i];
    }
  }

  return sum;
}

for (let i = 0; i < 10; i++) {
  setTimeout(function() { console.log(i); }, 100 * i);
}

let input = [1, 2];
let [first, second] = input;
console.log(first); // 1
console.log(second); // 2

function f([firs,t second]: [number, number]) {
  console.log(first);
  console.log(second);
}
f([1, 2]);

let [first, ...rest] = [1, 2, 3, 4];
console.log(first); // 1
console.log(second); // [2, 3, 4]

let [first] = [1, 2, 3, 4];
console.log(first); // 1

let [, second, , fourth] = [1, 2, 3, 4];

let o = {
  a: "foo",
  b: 12,
  c: "bar"
};

let { a, b } = o;

let { a, ...passthrough } = o;

let { a: newName1, b: newName2 } = o;

let { a, b }: { a: string, b: number} = o;

function keepWholeObject(wholeObject: { a: string, b?: number }) {
  let { a, b = 1001 } = wholeObject;
}

type C = { a:string, b?: number }
function f({ a, b }: C): void {
  // ...
}

let first = [1, 2];
let second = [3, 4];
let bothPlus [0, ...first, ...second, 5];-

class C {
  p = 12;
  m() {
  }
}
let c = new C();
let clone =  { ...c };
clone.p;
clone.m(); // error;