javascript - 延迟函数之间的简单函数

Question

假设我想通过清除 cookie 来登录和注销

function clearCookies() {
   ...
}

function login(username,password) {
   $.post(...).then(function(result){
       if(result == 1) {
           create();
       }
       else {
           login(username, password);
       }
   })
}

function create() {
     $.post(...).then(function(result){
         // create
     })
}

clearCookies当我遍历用户名时应该在哪里插入函数。

var data = [{"username":"_iamnumber4","password":"four"},{"username":"superman","password":"fantasic"}]

var promises = [];
$.each(data, function(k,v){
    promises.push(login(v.username, v.password));
});

$.when.apply($, promises).done(function() {
      console.log('all done');
});