Câu hỏi

bar();

var bar;

function bar() {
  console.log('first');
}

bar = function() {
  console.log('second');
};

bar();

foo();

function foo() {
  console.log(1);
}

var foo = function() {
  console.log(2);
};

function foo() {
  console.log(3);
}

foo();