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javascript-对象引用未按预期进行引用

javascript

A. L · 技术社区 · 7 年前

因此,我有以下代码:

async function runQuery(input)
{
  return input
}

async function createAccounts()
{
  return [1, 2]
}



(async function ()
{
  var
    creator1_ids =
        {},
    creator2_ids =
        {}

  let all_accounts =
    await createAccounts(2)

  const tables =
    [
      "list",
      "display_list",
      "map"
    ]

  for (let index in all_accounts)
  {
    let req =
      {
        session:
        {
          account:
            null
        }
      }
    req.session.account =
      all_accounts[index]
    let the_ids =
        index === 0
            ? creator1_ids
            : creator2_ids

    // Create item
    let result =
      await runQuery()

    the_ids.item = 
      1

    for (let table of tables)
    {
      result =
          await runQuery(table)
      the_ids[table] = 
          result
    }
  }
  
  console.log(creator1_ids)
  console.log(creator2_ids)  
})()

现在javascript使用对象作为引用(因此,如果将另一个变量指定给一个对象,则更改任何一个变量都会更改整个对象),但是这里的情况似乎不是这样。

creator1_ids creator2_ids 已经满了。我在等你 创建者1_id 以同样的方式填写。

async function runQuery(input)
{
  return input
}

async function createAccounts()
{
  return [1, 2]
}



(async function ()
{

    var
      creator1_ids =
          {},
      creator2_ids =
          {}
    let all_accounts =
        await createAccounts(2)

    const tables =
        [
            "list",
            "display_list",
            "map"
        ]

    async function generate(the_ids, account)
    {
       let req =
        {
          session:
          {
            account:
              null
          }
        }

      // Create item
      let result =
        await runQuery()

      the_ids.item = 
        1

      for (let table of tables)
      {
        result =
            await runQuery(table)
        the_ids[table] = 
            result + account
      }
    }

    await generate(creator1_ids, all_accounts[0])
    await generate(creator2_ids, all_accounts[1])

    console.log(creator1_ids)
    console.log(creator2_ids)
})()

2 回复 | 直到 7 年前

David 7 年前

结论无效,因为调试有缺陷。更仔细地查看调试器,特别是在这一行:

let the_ids =
  index === 0 ?
  creator1_ids :
  creator2_ids

index 从不等于 0 . 信息技术相同的 '0' . 所以 === 永远不会 true

更改比较,您将得到预期的结果:

let the_ids =
  index == 0 ? // compare values regardless of type
  creator1_ids :
  creator2_ids

然后您的循环将首先修改 creator1_ids creator2_ids . 演示:

async function runQuery(input) {
  return input
}

async function createAccounts() {
  return [1, 2]
}



(async function() {
  var creator1_ids = {},
    creator2_ids = {}

  let all_accounts = await createAccounts(2)

  const tables = [
    "list",
    "display_list",
    "map"
  ]

  for (let index in all_accounts) {
    let req = {
      session: {
        account: null
      }
    }
    req.session.account = all_accounts[index]
    let the_ids =
      index == 0 ?
      creator1_ids :
      creator2_ids

    // Create item
    let result = await runQuery()

    the_ids.item = 1

    for (let table of tables) {
      result = await runQuery(table)
      the_ids[table] = result
    }
  }

  console.log(creator1_ids)
  console.log(creator2_ids)
})()

imk 7 年前

指数一串所以使用引号。见下文

let the_ids = index === '0'? creator1_ids : creator2_ids

而不是

let the_ids = index === 0  ? creator1_ids: creator2_ids