lodash

I am looking for a way to filter a map by value instead of key. I have a data set that is modeled as follows in my Angular application: { "85d55e6b-f4bf-47bb-a988-78fdb9650ef0": { is_deleted: false, public_email: "007@example.org", id: "85d55e6b-f4bf-47bb-a988-78fdb9650ef0", modified_at: "2017-09-26T15:35:06.853492Z", social_url: "https://facebook.com/jamesbond007", event_id: "213b01de-da9e-4d19-8e9c-c0dae63e019c", visitor_id: "c3c232ff-1381-4776-a7f2-46c177ecde1c", }, } The keys on these entries are the same as the id field on the entries values. Given several of these entries, I would like

In my application If data is undefined or null which is coming from service, my html will not load and I will get "data is undefined" error so I am tring to use lodash, but dont know how to use it.. In my below ts file this._PartService.GetDataValues().subscribe( result => { this.distributionData = this._PartService.part_data.partMasterDataCompleteList[0].partMasterData.plantSupplies.plantSupply } I will be getting "partMasterDataCompleteList" as undefiend or null if data is not there, so there I am trying to use Lodash but I dont know how to use it Lodash provides quite a few methods to check

Here is a code snippet of an update method using express.js and mongoose. I'm trying to merge the existing mongo entity with the json object from the request payload body. exports.update = function(req, res) { if(req.body._id) { delete req.body._id; } Entity.findById(req.params.id, function (err, entity) { if (err) { return handleError(res, err); } if(!entity) { return res.send(404); } var updated = _.merge(entity, req.body); updated.save(function (err) { if (err) { return handleError(res, err); } return res.json(200, entity); }); }); }; This unfortunately doesn't work. I'm getting this error

I have following object records : { "notes":[ { "id":1, "description":"hey", "userId":2, "replyToId":null, "postId":2, "parentId":null }, { "id":5, "description":"hey test", "userId":3, "replyToId":null, "postId":2, "parentId":null }, { "id":2, "description":"how are you", "userId":null, "replyToId":2, "postId":2, "parentId":null, "user":null } ] } I want to output it as: 2 object with id 1 object with id 2 (because replyToId value is same as userId 3 object with id 5 So basically I want to consider UserId and replyToId value under the same group. I have build my own mixin under lodash,

What is an "authoritative" way to detect if the _ variable is loaded with lodash or underscore? I am using lodash for a project in an environment where underscore may sometimes also be loaded. Currently, I've come up with this: /** * lodash defines a variable PLACEHOLDER = '__lodash_placeholder__' * so check if that is defined / contains the string "lodash" */ if ( typeof( _.PLACEHOLDER ) == 'undefined' || _.PLACEHOLDER.indexOf( 'lodash' ) < 0 ) { // _ is underscore, do what I need to access lodash } Important update: The above code does NOT work! Is there an "authoritative" way to detect if _

I'm currently mapping through an array i.e. contents.map((content) => { switch(content.type) { case: 1 console.log("type is one and next type is .."); case: 2 console.log("type is two") } }) And as you can see in case 1 I need to grab type of next item. I know that this is possible using for loop with i increment, but need to do it within a map. I'm open for suggestions using libraries like lodash (wasn't able to find anything in the documentation). Array.prototype.map calls it's callback actually with 3 parameters: currentValue // current element index // current index array // original array

lodash：是一个一致性、模块化、高性能的 JavaScript 实用工具库。（也就是相当于自己封装的私有方法） node里引入 // Load the full build. var _ = require('lodash'); // Load the core build. var _ = require('lodash/core'); // Load the FP build for immutable auto-curried iteratee-first data-last methods. var fp = require('lodash/fp'); // Load method categories. var array = require('lodash/array'); var object = require('lodash/fp/object'); // Cherry-pick methods for smaller browserify/rollup/webpack bundles. var at = require('lodash/at'); var curryN = require('lodash/fp/curryN'); 举些使用的例子： _.chunk(array, [size=1])：按照size的大小来拆分array数组 _.chunk(['a