Underscore js find item by ID

Question

I'm new to Underscore js and bit confused on how to use it. I have a collection of 'goals' and I want to find one of it by ID.

here's the data:

{"goal":[     {         "category" : "education",         "title" : "Charlie University",         "description" : "Lorem ipsum dolor sit amet",         "date" : "01/03/2020",         "value" : 50000,         "achievability" : 3,         "experimental_achievability": 3,         "suggested": false,         "accounts": [             {                 ...             },             {                 ...             }         ],         "articles": [             {                 ...             },             {                 ...             },             {                 ...             }         ],         "related_goals": [             {                 ...             }         ],         "id":"1"     },     {         "category" : "family",         "title" : "Getting married",         "description" : "Lorem ipsum dolor sit amet",         "date" : "01/03/2022",         "value" : 10000,         "achievability" : 3,         "experimental_achievability": 2,         "suggested": true,         "accounts": [             {                 ...             }         ],         "articles": [             {                 ...             },             {                 ...             },             {                 ...             }         ],         "related_goals": [             {                 ...             }         ],         "id":"2"     }     ... ]} 

That's what I'm trying, I want to get the entire array/object so I can get each field of it:

var goalId = 1; _.each(result.goal, function(item){     _.find(result.goal, function(i){          return i = goalId;     }); }); 

Any idea how to do it?

Answer 1

Update

It's 2016 and we might not acutally need underscore to achieve that. Using Array.prototype.find(). It returns a value in the array, if an element in the array satisfies the provided testing function. Otherwise undefined is returned.

  // Underscore   var users = [     { 'user': 'barney',  'age': 36, 'active': true },     { 'user': 'fred',    'age': 40, 'active': false },     { 'user': 'pebbles', 'age': 1,  'active': true }   ]    _.find(users, function (o) { return o.age < 40; })   // output: object for 'barney'    // Native   var users = [     { 'user': 'barney',  'age': 36, 'active': true },     { 'user': 'fred',    'age': 40, 'active': false },     { 'user': 'pebbles', 'age': 1,  'active': true }   ]    users.find(function (o) { return o.age < 40; })   // output: object for 'barney' 

Browser support

-------------------------------------------- | Chrome | Firefox | Safari |  IE  | Opera | |--------|---------|--------|------|-------| |   45   |    25   |  7.1   | Edge |  32   | -------------------------------------------- 

More information an polyfill on MDN

---

Update: I found that _.where always returns an array. _.findWhere returns the first object it finds so it will be better to use if you expect a single object in return.

---

You can use _.where It's much easier.

If it's something like this :

var goal  = [      {         "category" : "education",         "title" : "Charlie University",         "description" : "Lorem ipsum dolor sit amet",         "date" : "01/03/2020",         "value" : 50000,         "achievability" : 3,         "experimental_achievability": 3,         "suggested": false,         "accounts": [],         "articles": [],         "related_goals": [],         "id":"1"     },     {         "category" : "education",         "title" : "Charlie University",         "description" : "Lorem ipsum dolor sit amet",         "date" : "01/03/2020",         "value" : 50000,         "achievability" : 3,         "experimental_achievability": 3,         "suggested": false,         "accounts": [],         "articles": [],         "related_goals": [],         "id":"2"     },     {         "category" : "education",         "title" : "Charlie University",         "description" : "Lorem ipsum dolor sit amet",         "date" : "01/03/2020",         "value" : 50000,         "achievability" : 3,         "experimental_achievability": 3,         "suggested": false,         "accounts": [],         "articles": [],         "related_goals": [],         "id":"3"     },     {         "category" : "education",         "title" : "Charlie University",         "description" : "Lorem ipsum dolor sit amet",         "date" : "01/03/2020",         "value" : 50000,         "achievability" : 3,         "experimental_achievability": 3,         "suggested": false,         "accounts": [],         "articles": [],         "related_goals": [],         "id":"4"     } ] 

You can use something like :

var filteredGoal = _.where(goal, {id: "1"}); 

Answer 2

You are using Array of objects. So,you can use: _.findWhere(Looks through the list and returns the first value that matches all of the key-value pairs ) to get the all the properties based on id or other key attribute.

var some= [              {Employee:'ved',id:20},               {Employee:"ved",age:25},              {Employee:"p",age:2}           ];  var a = _.findWhere(some,{id:20}); console.log('searchResult',a); 

To get the index, you can use something like this:

var b = _.indexOf(some,a); console.log('index',b); 

If you need all list of uses,
TRY: _.where(It looks through each occurrence in the array, returning an array of all the values that contain the key-value pairs listed in properties.)

var some= [              {Employee:"ved",id:20},              {Employee:"ved prakash",id:20},             {Employee:"anyone",id:2}           ]; var a = _.where(some,{id:25});     console.log('searchResult',a); 

_.find: It is used to check the value only, not Key-value both.

Visit Docs:_.find