如何动态附加到JavaScript数组？

Question

  

可能重复：
  How do I create Javascript array(JSON format) dynamically?

我正在尝试创建以下内容：

var employees = {"accounting": [   // accounting is an array in employees.
                    { "firstName" : "John",  // First element
                      "lastName"  : "Doe",
                      "age"       : 23 },

                    { "firstName" : "Mary",  // Second Element
                      "lastName"  : "Smith",
                      "age"       : 32 }
                  ] // End "accounting" array.                                  

    } // End Employees

我开始时：

 var employees=new Array();

如何继续动态追加数组（可能会将firstName更改为变量）？

Answer 1

var employees = {accounting: []};

employees.accounting.push({
    "firstName" : "New",
    "lastName"  : "Employee",
    "age"       : 18
});

Answer 2

employees.accounting.push({ "firstName" : "New",  // First element
                      "lastName"  : "Person",
                      "age"       : 55 });

Answer 3

var urNewFirstName='new john';
employees.accounting[0].firstName = urNewFistName;

Answer 4

function Employee(firstName, lastName, age) {
  this.firstName = firstName;
  this.lastName = lastName;
  this.age = age;
}

var employees = {};
employees.accounting = [];
employees.accounting.push(new Employee('John', 'Doe', 23));
employees.accounting.push(new Employee('Mary', 'Smith', 32));