如何在系列中执行承诺?

var promiseReturningFuncs = [];
for(var i = 0; i < 5; i++){
  promiseReturningFuncs.push(askQuestion);
}

var programmers = [];
Promise.reduce(promiseReturningFuncs, function(resp, x) {
  console.log(typeof resp);
  if(typeof resp != "function") {
    programmers.push(resp);
  }
  return x();
})
.then(function(resp) {
  programmers.push(resp);
  console.log(programmers);
});
var promiseReturningFuncs = [];
for(var i = 0;