Question

我在JavaScript中创建了一个对象，由于某种原因，它没有保存对象中的第17和第20项。

你可以通过下面的代码看到我的意思，第17和第10代。添加后，第20项不会记录到控制台。

为什么会这样，我必须遗漏一些明显的东西。我正在创建对象，因为我放入的值将用作整个AngularJS应用程序中可用的常量。

  var foo = { 
    001: { id: 001, name: "foo bar"}, 
    002: { id: 002, name: "foo bar"}, 
    003: { id: 003, name: "foo bar"}, 
    004: { id: 004, name: "foo bar"}, 
    005: { id: 005, name: "foo bar"}, 
    006: { id: 006, name: "foo bar"}, 
    007: { id: 007, name: "foo bar"}, 
    008: { id: 008, name: "foo bar"}, 
    009: { id: 009, name: "foo bar"}, 
    010: { id: 010, name: "foo bar"},
    011: { id: 011, name: "foo bar"}, 
    012: { id: 012, name: "foo bar"}, 
    013: { id: 013, name: "foo bar"}, 
    014: { id: 014, name: "foo bar"}, 
    015: { id: 015, name: "foo bar"}, 
    016: { id: 016, name: "foo bar"}, 
    017: { id: 017, name: "foo bar"},
    018: { id: 018, name: "foo bar"}, 
    019: { id: 019, name: "foo bar"}, 
    020: { id: 020, name: "foo bar"}
  }
  console.log(foo);

Answer 1

问题是Javascript中以0开头的数字文字被视为八进制（即基数为8）。所以020 === 16。如果数字以0开头但包含数字9或8（即它是无效的八进制数），则将其视为正常的十进制数。

因此，当您执行017和020时，它会被视为15和16，因此该属性会被写入两次。

如果您想要数字键，则需要将它们全部放在同一个基础上，因此丢失前导0。如果你想要字面意思020，那么你需要创建键和值字符串：

"001": { id: "001", name: "foo bar"}

Answer 2

那是因为这不是十进制数的有效格式。发生了什么事，你正在写octal numbers。基本上，它们是基数为8而不是10。

如果您希望它们位于基数10，请删除前导零。

var foo = { 
    1: { id: 1, name: "foo bar"}, 
    2: { id: 2, name: "foo bar"}, 
    3: { id: 3, name: "foo bar"}, 
    4: { id: 4, name: "foo bar"}, 
    5: { id: 5, name: "foo bar"}, 
    6: { id: 6, name: "foo bar"}, 
    7: { id: 7, name: "foo bar"}, 
    8: { id: 8, name: "foo bar"}, 
    9: { id: 9, name: "foo bar"}, 
    10: { id: 10, name: "foo bar"},
    11: { id: 11, name: "foo bar"}, 
    12: { id: 12, name: "foo bar"}, 
    13: { id: 13, name: "foo bar"}, 
    14: { id: 14, name: "foo bar"}, 
    15: { id: 15, name: "foo bar"}, 
    16: { id: 16, name: "foo bar"}, 
    17: { id: 17, name: "foo bar"},
    18: { id: 18, name: "foo bar"}, 
    19: { id: 19, name: "foo bar"}, 
    20: { id: 20, name: "foo bar"}
  }
  console.log(foo);

如果想要前导零，则需要使用字符串。

var foo = { 
    "001": { id: "001", name: "foo bar"}, 
    "002": { id: "002", name: "foo bar"}, 
    "003": { id: "003", name: "foo bar"}, 
    "004": { id: "004", name: "foo bar"}, 
    "005": { id: "005", name: "foo bar"}, 
    "006": { id: "006", name: "foo bar"}, 
    "007": { id: "007", name: "foo bar"}, 
    "008": { id: "008", name: "foo bar"}, 
    "009": { id: "009", name: "foo bar"}, 
    "010": { id: "010", name: "foo bar"},
    "011": { id: "011", name: "foo bar"}, 
    "012": { id: "012", name: "foo bar"}, 
    "013": { id: "013", name: "foo bar"}, 
    "014": { id: "014", name: "foo bar"}, 
    "015": { id: "015", name: "foo bar"}, 
    "016": { id: "016", name: "foo bar"}, 
    "017": { id: "017", name: "foo bar"},
    "018": { id: "018", name: "foo bar"}, 
    "019": { id: "019", name: "foo bar"}, 
    "020": { id: "020", name: "foo bar"}
  }
  console.log(foo);

Answer 3

我认为它与从0开始的数字有关，在javascript中被解释为八进制。所以017 = 15，你只需覆盖15的记录。

如果您将键名作为显式字符串，则可以正常工作。同样适用于内心＆＃39; id＆＃39;每条记录的关键。这就是为什么我不使用以数字开头的对象键，如果每个键只是一个索引，则使用数组。

 var foo = { 
    '001': { id: '001', name: "foo bar"}, 
    '002': { id: '002', name: "foo bar"}, 
    '003': { id: '003', name: "foo bar"}, 
    '004': { id: '004', name: "foo bar"}, 
    '005': { id: '005', name: "foo bar"}, 
    '006': { id: '006', name: "foo bar"}, 
    '007': { id: '007', name: "foo bar"}, 
    '008': { id: '008', name: "foo bar"}, 
    '009': { id: '009', name: "foo bar"}, 
    '010': { id: '010', name: "foo bar"},
    '011': { id: '011', name: "foo bar"}, 
    '012': { id: '012', name: "foo bar"}, 
    '013': { id: '013', name: "foo bar"}, 
    '014': { id: '014', name: "foo bar"}, 
    '015': { id: '015', name: "foo bar"}, 
    '016': { id: '016', name: "foo bar"}, 
    '017': { id: '017', name: "foo bar"},
    '018': { id: '018', name: "foo bar"}, 
    '019': { id: '019', name: "foo bar"}, 
    '020': { id: '020', name: "foo bar"}
  }
  console.log(JSON.stringify(foo));

Answer 4

因为前缀数字为0会告诉编译器（即浏览器）该数字是八进制且017 = 15

所有索引在转换为字符串时都要进行八进制到十进制转换（注意日志中的“”），有些将覆盖

其他数字（如019）不是有效的八进制值，所以它们的值保持十进制格式我认为

刚刚创建的Object I中缺少JavaScript项

4 个答案: