从嵌套对象的属性生成代码字符串

Question

我有一个按钮可以“编译”一个将在终端中使用的命令。
保持解释简单：
行里面有六个输入，行是一个对象，里面的输入是属性，输入的值是属性的值。 从输入数据写入终端命令。

JSON 对象如下所示

formsData = {
  transfer_1: {
    host_1: "t1_host1",
    host_2: "t1_host2",
    user_1: "t1_user1",
    user_2: "t1_user2",
    password_1: "t1_password1",
    password_2: "t1_password2"
  },
  transfer_2: {
    host_1: "t2_host1",
    host_2: "t2_host2",
    user_1: "t2_user1",
    user_2: "t2_user2",
    password_1: "t2_password1",
    password_2: "t2_password2"
  }
}

我想将 transfer_1 中的所有值放入终端的命令中，如下所示：

./imapsync --host1 t1_host1 --user1 t1_user1 --password1 t1_password1 
--host2 t1_host2 --user2 t1_user2 --password2 t1_password2;

我想做这样的事情：

var command = "";
for (i = 0; i < Object.keys(formsData).length; i++) {
    command += 
    "./imapsync_bin_Darwin " +
    "--host1 " + formsData[i].host_1 + " " +
    "--user1 " + formsData[i].user_1 + " " +
    "--password1 " + formsData[i].password_1 + " " +
    "--host2 " + formsData[i].host_2 + " " +
    "--user2 " + formsData[i].user_2 + " " +
    "--password2 " + formsData[i].password_2 + "; ";
}
console.log(command);

但我得到的只是

Uncaught TypeError: Cannot read property 'host_1' of undefined

编辑： 非常感谢您的快速回答！多亏了你们，它现在可以工作了，我希望我现在变得更聪明了:-)

Answer 1

因为你需要通过键名来获取它，就像那样（快速示例）；

var formsData = {
  transfer_1: {
    host_1: "t1_host1",
    host_2: "t1_host2",
    user_1: "t1_user1",
    user_2: "t1_user2",
    password_1: "t1_password1",
    password_2: "t1_password2"
  },
  transfer_2: {
    host_1: "t2_host1",
    host_2: "t2_host2",
    user_1: "t2_user1",
    user_2: "t2_user2",
    password_1: "t2_password1",
    password_2: "t2_password2"
  }
};

var command = "",
    keys = Object.keys(formsData);

for (i = 0; i < keys.length; i++) {
    command += 
    "./imapsync_bin_Darwin " +
    "--host1 " + formsData[keys[i]].host_1 + " " +
    "--user1 " + formsData[keys[i]].user_1 + " " +
    "--password1 " + formsData[keys[i]].password_1 + " " +
    "--host2 " + formsData[keys[i]].host_2 + " " +
    "--user2 " + formsData[keys[i]].user_2 + " " +
    "--password2 " + formsData[keys[i]].password_2 + "; ";
}
console.log(command);

Answer 2

试试这个，

var formsData = {
  transfer_1: {
    host_1: "t1_host1",
    host_2: "t1_host2",
    user_1: "t1_user1",
    user_2: "t1_user2",
    password_1: "t1_password1",
    password_2: "t1_password2"
  },
  transfer_2: {
    host_1: "t2_host1",
    host_2: "t2_host2",
    user_1: "t2_user1",
    user_2: "t2_user2",
    password_1: "t2_password1",
    password_2: "t2_password2"
  }
};
var command = "";
var keys=Object.keys(formsData);
for (var i=0,l=keys.length;i<l;i++) {
    t=formsData[keys[i]];
    command += 
    "./imapsync_bin_Darwin " +
    "--host1 " + t.host_1 + " " +
    "--user1 " + t.user_1 + " " +
    "--password1 " + t.password_1 + " " +
    "--host2 " + t.host_2 + " " +
    "--user2 " + t.user_2 + " " +
    "--password2 " + t.password_2 + "; ";
}
console.log(command);

Answer 3

您混淆了数组和对象。

formsData 是一个对象，但您使用它就像一个数组（尝试获取 length 并使用索引对其进行迭代）。使用for (var key in formsData) 和hasOwnProperty 之后检查对象。

像这样（未经测试，但你明白了）：

var command = "";
for (var key in formsData) {
    if (!formsData.hasOwnProperty(key)) continue;
    command += 
    "./imapsync_bin_Darwin " +
    "--host1 " + formsData[key].host_1 + " " +
    "--user1 " + formsData[key].user_1 + " " +
    "--password1 " + formsData[key].password_1 + " " +
    "--host2 " + formsData[key].host_2 + " " +
    "--user2 " + formsData[key].user_2 + " " +
    "--password2 " + formsData[key].password_2 + "; ";
}
console.log(command);

您可能希望在第一个键（“transfer_1”）之后中断以获得您真正想要的东西（“将 transfer_1 中的所有值放入命令中”）。所以你实际上可以不用循环，只分配var key = "transfer_1"。

对于更短的方法，您可以像这样做得更漂亮：

var formsData = {
  transfer_1: {
    host_1: "t1_host1",
    host_2: "t1_host2",
    user_1: "t1_user1",
    user_2: "t1_user2",
    password_1: "t1_password1",
    password_2: "t1_password2"
  },
  transfer_2: {
    host_1: "t2_host1",
    host_2: "t2_host2",
    user_1: "t2_user1",
    user_2: "t2_user2",
    password_1: "t2_password1",
    password_2: "t2_password2"
  }
}

var command = "./imapsync_bin_Darwin ";
for (var key in formsData.transfer_1) {
    if (!formsData.transfer_1.hasOwnProperty(key)) continue;
    command += "--" + key + " " + formsData.transfer_1[key] + " ";
}
command = command.slice(0,-1) + ";";
console.log(command);

 

Answer 4

循环中的i 是计数键，formsData 中有 2 个键。所以i 取值 0 和 1。当你执行 formsData[i] 时，实际上是在执行 formsData[0] 或 formsData[1]，这两者都不存在。这就是你不确定的原因。

您可能想试试formsData[keys[i]]。这样keys[i] 将采用值“transfer_1”和“transfer_2”，因此formsData["transfer_1"].host_1 突然变为有效。