Select 不同的子数组属性 LoDash

Question

模型结构如下：

prods: [{
        code: 'ABC123',
        name: 'Product 1',
        variants[{
                code: 'V123',
                name 'Var 1'
            }, {
                code: 'V456',
                name 'Var 2'
            }, {
                code: 'V789',
                name 'Var 3'
            }
        ]
    }, {
        code: 'DEF456',
        name: 'Product 2',
        variants[{
                code: 'V098',
                name 'Var 4'
            }, {
                code: 'V123',
                name 'Var 1'
            }, {
                code: 'V123',
                name 'Var 1'
            }
        ]
    }, {
        code: 'XYZ123',
        name: 'Product 3',
        variants[{
                code: 'V123',
                name 'Var 1'
            }, {
                code: 'V456',
                name 'Var 2'
            }, {
                code: 'V789',
                name 'Var 3'
            }
        ]
    }
]

是否有可能获得一组独特的变体代码，所以希望输出给我：

[{code:'V123'},{code: 'V456'}, {code: 'V789'},{code: 'V098'}]

Answer 1

你可以链接在一起[=13=]:

_(prods)
  .map('variants')
  .flatten()
  .uniqBy('code')
  .map(i => _.pick(i, 'code'))
  .value();

第二个 map() 调用并非绝对必要 - 它只是为了摆脱 name 属性以匹配您请求的输出。

Answer 2

您可以使用 flatMap to get all variants, complemented with map and uniqBy 获取所有唯一代码。

var result = _(prods)
  .flatMap('variants')
  .uniqBy('code')
  .map(_.partialRight(_.pick, 'code'))
  .value();

var prods = [{
  code: 'ABC123',
  name: 'Product 1',
  variants: [{
    code: 'V123',
    name: 'Var 1'
  }, {
    code: 'V456',
    name: 'Var 2'
  }, {
    code: 'V789',
    name: 'Var 3'
  }]
}, {
  code: 'DEF456',
  name: 'Product 2',
  variants: [{
    code: 'V098',
    name: 'Var 4'
  }, {
    code: 'V123',
    name: 'Var 1'
  }, {
    code: 'V123',
    name: 'Var 1'
  }]
}, {
  code: 'XYZ123',
  name: 'Product 3',
  variants: [{
    code: 'V123',
    name: 'Var 1'
  }, {
    code: 'V456',
    name: 'Var 2'
  }, {
    code: 'V789',
    name: 'Var 3'
  }]
}];

var result = _(prods)
  .flatMap('variants')
  .uniqBy('code')
  .map(_.partialRight(_.pick, 'code'))
  .value();
  
console.log(result);

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