Find object by match property in nested array

问题

I'm not seeing a way to find objects when my condition would involve a nested array.

var modules = [{
    name: 'Module1',
    submodules: [{
        name: 'Submodule1',
        id: 1
      }, {
        name: 'Submodule2',
        id: 2
      }
    ]
  }, {
    name: 'Module2',
    submodules: [{
        name: 'Submodule1',
        id: 3
      }, {
        name: 'Submodule2',
        id: 4
      }
    ]
  }
];

This won't work because submodules is an array, not an object. Is there any shorthand that would make this work? I'm trying to avoid iterating the array manually.

_.where(modules, {submodules:{id:3}});

回答1:

Here's what I came up with:

_.find(modules, _.flow(
    _.property('submodules'),
    _.partialRight(_.some, { id: 2 })
));
// → { name: 'Module1', ... }

Using flow(), you can construct a callback function that does what you need. When call, the data flows through each function. The first thing you want is the submodules property, and you can get that using the property() function.

The the submodules array is then fed into some(), which returns true if it contains the submodule you're after, in this case, ID 2.

Replace find() with filter() if you're looking for multiple modules, and not just the first one found.

回答2:

Lodash allows you to filter in nested data (including arrays) like this:

_.filter(modules, { submodules: [ { id: 2 } ]});

回答3:

I think your best chance is using a function, for obtaining the module.

_.select(modules, function (module) {
  return _.any(module.submodules, function (submodule) {
    return _.where(submodule, {id:3});
  });
});

try this for getting the submodule

.where(.pluck(modules, "submodules"), {submodules:{id:3}});

来源：https://stackoverflow.com/questions/30107463/find-object-by-match-property-in-nested-array

标签

lodash