Question

我有一个数组，我不知道如何访问某些键。我想要完成的只是针对数组中的某些键/值。这是我的数组样本。

var jobs = [
    {
        // hunting
        name: 'Hunting',
        available: [
            {
                name: 'Housemate',
                description: 'You stick around the cabin of the hunters. You are the lowest class of the hunters.',
                salary: 10
            },
            {
                name: 'Fetcher',
                description: 'You are the fetcher of the clan. You gather leather, resources, and skin leather.',
                salary: 15
            },
            {
                name: 'Hunter',
                description: 'You are a basic hunter of the clan. You hunt for food, meat, and leather.',
                salary: 25
            },
            {
                name: 'Elder',
                description: 'You are a elder of the clan. You are respected among many, and may ask hunters for arrons.',
                salary: 0
            }
        ],
        // construction
        name: 'Construction',
        available: [
            {
                name: 'Builder',
                description: 'You are a builder. You are the lowest class of the construction tier.',
                salary: 45

            },
            {
                name: 'Driver',
                description: 'You are a driver. You do the fetching and gathering of resources.',
                salary: 55
            },
            {
                name: 'Engineer',
                description: 'You are a engineer. You do the wiring and electrical work in the construction.',
                salary: 65
            },
            {
                name: 'Overseer',
                description: 'You are the overseer. You watch over the construction and give orders.',
                salary: 80
            }
        ],
    }
];

现在请记住，我在一个数组中有多个数组。在这里，我尝试访问Hunter工作类别，Fetcher工作和建筑工程师工资。

alert(jobs.'Hunting'); // gives 'missing name after . operator' error
alert(jobs.name[0]); // gives 'name is not defined' error
alert(jobs.available.'Fetcher'); //same error as number 1
alert(jobs.available.salary[0]) // gives available is not defined error

如何访问这些变量？

Answer 1

我冒昧地修复了你的例子中的语法错误。正如你在评论中看到的那样，Hunter和Construction之间缺少紧密/开放的支撑。

  }]},
    // construction
            {name: 'Construction',

您需要使用索引表示法来获取数组中的不同元素。

这将返回Hunter对象。从那里您可以访问各个元素（名称或可用）。

console.log(jobs[0]);

这将为您提供第一个对象的名称属性的名称。

console.log(jobs[0].name);

这将返回可用的第一个对象。

console.log(jobs[0].available[0]);

这将从可用的第一个对象返回name属性。

console.log(jobs[0].available[0].name);

Here is a fiddle I created

Answer 2

您的对象数组格式错误

您的原始数组包含一个项目：一个对象已定义两次name和available属性。

我怀疑你希望你的数组包含两个项目：两个对象，每个对象都有name和available属性。

应该是这样的：

var jobs = [
    {
        // hunting
        name: 'Hunting',
        available: [
            {
                name: 'Housemate',
                description: 'You stick around the cabin of the hunters. You are the lowest class of the hunters.',
                salary: 10
            }, {
                name: 'Fetcher',
                description: 'You are the fetcher of the clan. You gather leather, resources, and skin leather.',
                salary: 15
            },  {
                name: 'Hunter',
                description: 'You are a basic hunter of the clan. You hunt for food, meat, and leather.',
                salary: 25
            },  {
                name: 'Elder',
                description: 'You are a elder of the clan. You are respected among many, and may ask hunters for arrons.',
                salary: 0
            }
        ]
    }, {
        // construction
        name: 'Construction',
        available: [
            {
                name: 'Builder',
                description: 'You are a builder. You are the lowest class of the construction tier.',
                salary: 45

            }, {
                name: 'Driver',
                description: 'You are a driver. You do the fetching and gathering of resources.',
                salary: 55
            }, {
                name: 'Engineer',
                description: 'You are a engineer. You do the wiring and electrical work in the construction.',
                salary: 65
            },  {
                name: 'Overseer',
                description: 'You are the overseer. You watch over the construction and give orders.',
                salary: 80
            }
        ],
    }
];

访问数组中的项目

alert(jobs[0].name);                // Returns 'Hunting'
alert(jobs[0].available[1].name);   // Returns 'Fetcher'
alert(jobs[0].available[3].salary); // Returns '0'

以下示例为何不起作用？

您不能以点表示法使用字符串：

alert(jobs.'Hunting');
alert(jobs.available.'Fetcher');

点后面不能有字符串。您应该拥有object.name中的属性名称，但首先需要通过其索引定义您在array[i].name中定位的数组中的哪个项目。

但即使你把它改为......

alert(jobs[0].Hunting); // OR
alert(jobs[0]['Hunting']);

...它会失败，因为没有具有属性名称'Hunting'的对象。

方括号错位：

alert(jobs.name[0]);
alert(jobs.available.salary[0]);

上面的示例不起作用，因为您在属性名称后面的方括号内传递索引，它们应放在数组名称后面。例如：

alert(jobs[0].name);
alert(jobs[0].available[0].salary);

按键/值

访问数组中的对象

看起来你正试图通过其中一个属性的值来访问数组中的对象。

例如，上面似乎您想要获取name的属性值为'Hunting' 的对象，这不能直接完成。

您需要创建一个函数或使用为此提供函数的库，例如Underscore's _.find。

使用_.find按键/值获取对象的示例：

var hunting = _.find(jobs, function(obj) { return obj.name === 'Hunting'; });

View the above examples in JSFiddle

Answer 3

您没有正确构建对象，请执行以下操作：

var jobs = {
    // New child object create only for Hunting
    hunting: {
        // hunting
        name: 'Hunting', // optional
        available: [
            {
                name: 'Housemate',
                description: 'You stick around the cabin of the hunters. You are the lowest class of the hunters.',
                salary: 10
            },
            {
                name: 'Fetcher',
                description: 'You are the fetcher of the clan. You gather leather, resources, and skin leather.',
                salary: 15
            },
            {
                name: 'Hunter',
                description: 'You are a basic hunter of the clan. You hunt for food, meat, and leather.',
                salary: 25
            },
            {
                name: 'Elder',
                description: 'You are a elder of the clan. You are respected among many, and may ask hunters for arrons.',
                salary: 0
            }
        ]
     },
     // Other section, this time for Construction
     construction : {
        // construction
        name: 'Construction', // Optional too
        available: [
            {
                name: 'Builder',
                description: 'You are a builder. You are the lowest class of the construction tier.',
                salary: 45

            },
            {
                name: 'Driver',
                description: 'You are a driver. You do the fetching and gathering of resources.',
                salary: 55
            },
            {
                name: 'Engineer',
                description: 'You are a engineer. You do the wiring and electrical work in the construction.',
                salary: 65
            },
            {
                name: 'Overseer',
                description: 'You are the overseer. You watch over the construction and give orders.',
                salary: 80
            }
        ],
    }
};

现在你可以做到：

var construction_jobs = jobs.construction.available;

如果你绝对想要保持阵列的第一维，你可以这样做：

var jobs = [
    {
        // hunting
        name: 'Hunting', 
        available: [ /* objects... */ ]
     },
     {
        // construction
        name: 'Construction', 
        available: [ /* objects... */ ]
    }
];

使用lodash lib获取数据：

var job = _.findWhere(jobs, {name: 'Hunting'});

要理解，请检查此codepen上的控制台日志显示：http://codepen.io/ArthyFiciel/pen/waGxrm

如何访问多维数组（像这样）？

3 个答案:

您的对象数组格式错误

访问数组中的项目

以下示例为何不起作用？

按键/值