如何一个接一个地执行函数？

function func1(callback) {
  console.log("Function 1");
  callback();
}

function func2(callback) {
  console.log("Function 2");
  callback();
}

function func3(callback) {
  console.log("Function 3");
  callback();
}

func1(function() {
  func2(function() {
    func3(function() {
      console.log("All functions executed");
    });
  });
});

function func1() {
  return new Promise(function(resolve, reject) {
    console.log("Function 1");
    resolve();
  });
}

function func2() {
  return new Promise(function(resolve, reject) {
    console.log("Function 2");
    resolve();
  });
}

function func3() {
  return new Promise(function(resolve, reject) {
    console.log("Function 3");
    resolve();
  });
}

func1()
  .then(func2)
  .then(func3)
  .then(function() {
    console.log("All functions executed");
  });