create an array of objects from an object and array

create an array of objects from an object and array - javascript

I have an object:
items = {
0: "foo",
1: "bar",
2: "baz"
};
and an array:
category = [
"type1",
"type2",
"type3"
];
I want to merge these with the desired output:
newArray = [
{type1:"foo"},
{type2:"bar"},
{type3:"baz"}
];
I thought I would be able to do it quite simply with a for loop like the following (though any method would do):
var obj = {};
for (var i = 0; i < category.length; i++) {
obj [category[i]] = items[i];
newArray.push(obj);
}
What I actually get is :
[{"type1":"foo","type2":"bar","type3":"baz"},
{"type1":"foo","type2":"bar","type3":"baz"},
{"type1":"foo","type2":"bar","type3":"baz"}]
I guess it's iterating through all instances of i for each obj each time but how do I amend to get the desired output?
https://jsfiddle.net/ormxq0y4/3/

you want a new object for each iteration
for (var i = 0; i < category.length; i++) {
var obj = {};
obj [category[i]] = items[i];
newArray.push(obj);
}

I guess this should do it;
var items = {
0: "foo",
1: "bar",
2: "baz"
},
category = [
"type1",
"type2",
"type3"
],
newArray = category.map((e,i) => ({[e]:items[i]}));
console.log(newArray)

You could try something like this ->
category.forEach(function (e,i) {
var obj = {};
obj[e] = items[i];
newArray.push(obj);
});

var items = {
0: "foo",
1: "bar",
2: "baz"
},
category = [
"type1",
"type2",
"type3"
];
var reformattedArray = category.map(function(obj, index){
var rObj = {};
rObj[obj] = items[index];
return rObj;
});
console.log("reformattedArray", reformattedArray);
https://jsfiddle.net/s6ntL2eo/

Here is how i would do it. But in my honest opinion is a bit risky if you relay only on the items KEY to be the connection point for the array. Please also keep in mind that an object allows the key to be eigther string or number (that's why items[+key]).
var items = {
0: "foo",
1: "bar",
2: "baz"
};
var categories = [
"type1",
"type2",
"type3"
];
var newArray = [];
categories.forEach(function (category, key) {
if (items[+key]) {
var tmpO = {};
tmpO[category] = items[+key];
newArray.push(tmpO);
}
});
console.log(newArray)

You are not making a separate object each time. Instead you are pushing the same object three times, and adding type1, type2, type3 properties to this one object.
Simply moving var obj = {} into the loop fixes your issue.
newArray = [];
items = {
0: "foo",
1: "bar",
2: "baz"
};
category = [
"type1",
"type2",
"type3"
];
for (var i = 0; i < category.length; i++) {
var obj = {};
obj[category[i]] = items[i];
newArray.push(obj);
}
var title = document.getElementById("title");
title.innerHTML = JSON.stringify(newArray);
With the result: [{"type1":"foo"},{"type2":"bar"},{"type3":"baz"}]

Related

Converting an array of 3 arrays into 1 big array with object variable

I'm new to StackOverflow and I know this post might possibly be a duplicate of another so please spare me with all the downvotes and if you think there's an answer to my question out there, please post it and I'll delete this question. Thanks for understanding.
var array1 = ["name", "title", "desc"]
var array2 = [["name1", "name2"], ["title1", "title2"],["desc1", "desc2"]]
How will I turn these into:
[
{name: "name1", title: "title1", desc: "desc1"},
{name: "name2", title: "title2", desc: "desc2"}
]

You can use Array#map, Object.assign (with spread syntax) and the ES6 computed property syntax to achieve that:
const array1 = ["name", "title", "desc"],
array2 = [["name1", "name2"], ["title1", "title2"],["desc1", "desc2"]];
const result = array2[0].map( (_, j) =>
Object.assign(...array1.map( (key, i) => ({ [key]: array2[i][j] }) ))
);
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

const result = [];
for(const [index, key] of array1.entries()){
for(const [userindex, value] of array2[index].entries()){
if(!result[userindex])
result[userindex] = {};
result[userindex][key] = value;
}
}
You might go over every key and the values related to the key and assign every key/value pair to the resulting object at the position of the value.

You could reduce the given values array by using the keys as key and the value for new objects.
var keys = ["name", "title", "desc"],
values = [["name1", "name2"], ["title1", "title2"],["desc1", "desc2"]],
objects = values.reduce((r, a, i) => {
a.forEach((v, j) => Object.assign(r[j] = r[j] || {}, { [keys[i]]: v }));
return r;
}, []);
console.log(objects);

You can use this way also:
var array1 = ["name", "title", "desc"];
var array2 = [["name1", "name2"], ["title1", "title2"],["desc1", "desc2"]];
var res = [];
for(var i=0; i<array2[0].length; i++){
var obj = {};
for(var j=0; j<array1.length; j++){
var key = array1[j];
var value = array2[j][i];
obj[key] = value;
}
res.push(obj);
}
console.log(res);

javascript array of object with key

I've been searching and searching and haven't found a solution...even though, likely, it's simple. How do I create something that will give me this:
myArray['key1'].FirstName = "First1";
myArray['key1'].LastName = "Last1";
myArray['key2'].FirstName = "First2";
myArray['key2'].LastName = "Last2";
myArray['key3'].FirstName = "First3";
myArray['key3'].LastName = "Last3";
And then say something like, alert(myArray['key2'].FirstName);
And will I be able to iterate through it like:
for(i=0; i < myArray.length; i++){
//do whatever
}
Thanks in advance!

You can init an object something like that:
{
"key1": {FirstName: "first1", LastName: "last1"}
"key2": {FirstName: "first2", LastName: "last2"}
"key3": {FirstName: "first3", LastName: "last3"}
}
Sample function for init your array:
function initArray(){
for(var i=1; i< count+1; i++) {
var newElement = {}
newElement.FirstName = "first" + i;
newElement.LastName = "last" + i;
var keyName = "key" + i
var obj = {};
myArray[keyName] = newElement
}
}
Now "myArray["key2"] is accessible.
http://jsfiddle.net/jq5Cf/18/

You can't do what you're trying to do in javascript! (because javascript can't do associative arrays)
I would go for an object which has an internal array to store other things
var container = {};
container.things = [];
container.things.push({FirstName: 'First1', LastName: 'Last1'});
now you can do..
for(var i in container.things) {
alert(container.things[i].FirstName);
}

In JavaScript we use arrays like this, [] for Arrays and Objects are in {}
var MyArray = [
{FirstName: "Firsname1" , LastName: "Lasname1"},
{FirstName: "Firsname2" , LastName: "Lasname2"}
]

Your myarray variable construction is in notation of objects of objects.
var myArray = {'key1':
{
'FirstName' : "First1",
'LastName' : "Last1"
}};
In order to access the values should be like array of objects.
var myArray = [
{
'FirstName' : "First1",
'LastName' : "Last1"
},
];
or notation can be like below:
var data = {
code: 42,
items: [{
id: 1,
name: 'foo'
}, {
id: 2,
name: 'bar'
}]
};

Get all possible options for a matrix in javascript

I have an 'item' object in JavaScript, and the item can have settings like
color, size, etc.
I need to get all possible combinations in an array.
So lets say we have an item that looks like this:
var newItem = {
name: 'new item',
Settings: [
{name: 'color', values: ['green', 'blue', 'red']},
{name: 'size', values: ['15', '18', '22']},
{name: 'gender',values: ['male', 'female']}
]
};
I need to somehow get this:
[
[{SettingName:'color',value:'green'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'blue'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'red'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'green'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'blue'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'red'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'green'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'blue'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'red'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'male'}],
[{SettingName:'color',value:'green'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'blue'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'red'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'green'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'blue'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'red'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'green'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'blue'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'female'}],
[{SettingName:'color',value:'red'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'female'}]
]

This can be a good interview question.
See JS Bin for running example.
getAllPermutations(newItem);
function getAllPermutations(item) {
var permutations = [];
getAllPermutations0(item, permutations, []);
console.log(permutations);
}
function getAllPermutations0(item, permutations, array) {
if (array && array.length === item.Settings.length) {
permutations.push(array.slice()); // The slice clone the array
return;
}
var index = array.length;
var setting = item.Settings[index];
for (var i = 0; i < setting.values.length; i++) {
if (index === 0)
array = [];
var currValue = setting.values[i];
array.push({
SettingName: setting.name,
value: currValue
});
getAllPermutations0(item, permutations, array);
array.pop(); // pop the old one first
}
}

Here is a none recursive solution. It takes an empty or existing settings "matrix" and a values array, and return a new matrix as a combination of existing matrix content cloned for each new value, appended with pairs of new value setting items.
[A] -> [1,2] gives [A][1][A][2]
[A][1][A][2] -> [X,Y] gives [A][1][X][A][2][Y][A][2][X][A][1][Y]
and so on
function processSettings(settings, name, values) {
if (settings.length == 0) {
values.forEach(function(value) {
settings.push( [{ SettingName: name, value: value }] )
})
} else {
var oldSettings = JSON.parse(JSON.stringify(settings)), settings = [], temp, i = 0
for (i; i<values.length; i++) {
temp = JSON.parse(JSON.stringify(oldSettings))
temp.forEach(function(setting) {
setting.push( { SettingName: name, value: values[i] } )
settings.push(setting)
})
}
}
return settings
}
You can now create the desired settings literal this way :
var settings = []
for (var i=0; i<newItem.Settings.length; i++) {
var item = newItem.Settings[i]
settings = processSettings(settings, item.name, item.values)
}
demo -> http://jsfiddle.net/b4ck98mf/
The above produces this :
[
[{"SettingName":"color","value":"green"},{"SettingName":"size","value":"15"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"blue"},{"SettingName":"size","value":"15"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"red"},{"SettingName":"size","value":"15"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"green"},{"SettingName":"size","value":"18"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"blue"},{"SettingName":"size","value":"18"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"red"},{"SettingName":"size","value":"18"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"green"},{"SettingName":"size","value":"22"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"blue"},{"SettingName":"size","value":"22"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"red"},{"SettingName":"size","value":"22"},{"SettingName":"gender","value":"male"}],
[{"SettingName":"color","value":"green"},{"SettingName":"size","value":"15"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"blue"},{"SettingName":"size","value":"15"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"red"},{"SettingName":"size","value":"15"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"green"},{"SettingName":"size","value":"18"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"blue"},{"SettingName":"size","value":"18"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"red"},{"SettingName":"size","value":"18"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"green"},{"SettingName":"size","value":"22"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"blue"},{"SettingName":"size","value":"22"},{"SettingName":"gender","value":"female"}],
[{"SettingName":"color","value":"red"},{"SettingName":"size","value":"22"},{"SettingName":"gender","value":"female"}]
]

You can use Array.prototype.map(), for loop, while loop, Array.prototype.concat(). Iterate gender values; select each of color, size value in succession beginning at index 0 of either; iterating the furthest adjacent array from current gender, increment the index of the closest adjacent array; merge the resulting two gender arrays to form a single array containing all combinations of gender, color, size
var colors = newItem.Settings[0].values;
var sizes = newItem.Settings[1].values;
var gen = newItem.Settings[2].values;
var i = sizes.length;
var res = [].concat.apply([], gen.map(function(value, key) {
var next = -1;
var arr = [];
for (var curr = 0; curr < i; curr++) {
while (next < i - 1) {
arr.push([{
SettingName: "gender",
value: value
}, {
SettingName: "size",
value: sizes[curr]
}, {
SettingName: "color",
value: colors[++next]
}])
}
next = -1;
}
return arr
}))
var newItem = {
"name": "new item",
"Settings": [{
"name": "color",
"values": [
"green",
"blue",
"red"
]
}, {
"name": "size",
"values": [
"15",
"18",
"22"
]
}, {
"name": "gender",
"values": [
"male",
"female"
]
}]
}
var colors = newItem.Settings[0].values;
var sizes = newItem.Settings[1].values;
var gen = newItem.Settings[2].values;
var i = sizes.length;
var res = [].concat.apply([], gen.map(function(value, key) {
var next = -1;
var arr = [];
for (var curr = 0; curr < i; curr++) {
while (next < i - 1) {
arr.push([{
SettingName: "gender",
value: value
}, {
SettingName: "size",
value: sizes[curr]
}, {
SettingName: "color",
value: colors[++next]
}])
}
next = -1;
}
return arr
}))
document.querySelector("pre").textContent = JSON.stringify(res, null, 2)
<pre></pre>
plnkr http://plnkr.co/edit/C2fOJpfwOrlBwHLQ2izh?p=preview

An approach using Array.prototype.reduce(), Array.prototype.sort(), Object.keys(), for loop, while loop
var newItem = {
name: 'new item',
Settings: [
{
name: 'color',
values: ['green', 'blue', 'red']
},
{
name: 'size',
values: ['15', '18', '22']
},
{
name: 'gender',
values: ['male', 'female']
}
]
};
var props = ["SettingName", "value"];
var settings = newItem.Settings;
function p(settings, props) {
var data = settings.reduce(function(res, setting, index) {
var name = setting.name;
var obj = {};
obj[name] = setting.values;
res.push(obj);
return res.length < index ? res : res.sort(function(a, b) {
return a[Object.keys(a)[0]].length - b[Object.keys(b)[0]].length
})
}, []);
var key = data.splice(0, 1)[0];
return [].concat.apply([], key[Object.keys(key)].map(function(value, index) {
return data.reduce(function(v, k) {
var keys = [v, k].map(function(obj) {
return Object.keys(obj)[0]
});
var i = Math.max.apply(Math, [v[keys[0]].length, k[keys[1]].length]);
var next = -1;
var arr = [];
for (var curr = 0; curr < i; curr++) {
while (next < i - 1) {
var a = {};
a[props[0]] = keys[0];
a[props[1]] = v[keys[0]][++next];
var b = {};
b[props[0]] = keys[1];
b[props[1]] = k[keys[1]][next];
var c = {};
c[props[0]] = Object.keys(key)[0];
c[props[1]] = value;
arr.push([a, b, c]);
};
next = -1;
}
return arr
});
}));
}
document.querySelector("pre").textContent = JSON.stringify(
p(settings, props), null, 2
);
<pre></pre>

re building a json from an exciting one nodejs

I've the current JSON that looks like this
{
"_id": "5371f7171b27d11418bd9b46",
"name": "a",
"length": 14
},
{
"_id": "5371f7171b27d1143bd9b46",
"name": "ab",
"length": 3
}
and I'm trying to get it to look like this one,
5371f7171b27d11418bd9b46: {
name: "a",
length: 14,
toc: [] // in the future it will be in the json I get.
},
5371f7171b27d1143bd9b46: {
name: "ab",
length: 3,
toc: []
}
this is what I tried,
var arrenged = {};
_.forEach(result, function(item) {
arrenged[item._id] = arrenged[item._id] || {};
arrenged[item._id][item.name] = arrenged[item._id][item.name] || {};
arrenged[item._id][item.name].push(item);
arrenged[item._id]['direction'] = 'rtl';
arrenged[item._id]['toc'] = "[]";
});
res.jsonp(arrenged);
but I get TypeError: Object # has no method 'push', not sure what I'm doing wrong.
thanks!

Could just do:
var newObject = {};
for (var i = 0; i < data.length; i++) { //data is your current array of objects
var id = data[i]._id;
newObject[id] = {};
newObject[id].name = data[i].name;
newObject[id].length = data[i].length;
newObject[id].toc = [];
}
Fiddle: http://jsfiddle.net/KWjb3/

Split array of objects into new array or objects based on age value

Split array of objects into new array or objects based on age value in Javascript
var items = [
{name:"Foo", age:16, color:"w"},
{name:"Bar", age:18, color:"b"},
{name:"foo", age:16, color:"w"},
{name:"bar", age:18, color:"w"},
{name:"foobar", age:18, color:"b"},
{name:"barfoo", age:20, color:"w"}
];
How can I return a list like:
var items = [
{age:16,name:"Foo"|"foo",gender:"w"|"w"},
{age:18,name:"Bar"|"bar"|"foobar",gender:"b"|"w"|"b"},
{age:20,name:"barfoo",gender:"w"}
];
I have worked but i got output with 'undefined' in name. Below is my code.
var data = [{age: 21,name: "Walter",color: "black"},{age: 25,name: "sentinel",color: "black"
},{age: 21,name: "Micah",color: "purple"},{age: 25,name: "mike",color: "black"},{age: 21,name: "Danny",color: "white"},{age: 25,name: "mike",color: "black"}];
var obj=data;
var arrayobj = obj.length;
var i, row, arr = obj, ss = {};
for (i = 0; i < arr.length; i++) {
row = arr[i];
ss[row.age] = ss[row.age] || {count: 0};
if (ss[row.age][row.age] === undefined) {
ss[row.age][row.name] = row.name;
ss[row.age]['name']+=row.name+'|';
ss[row.age]['color']+=row.color+'|';
ss[row.age]['count'] += 1;
}
}
console.table(ss);

I'm assuming you want to group the items by their age. Here is one way:
(fiddle)
items.reduce(function(buckets,item){
if(!buckets[item.age]) buckets[item.age] = [];
buckets[item.age].push(item);
return buckets;
},{});
Let's explain:
For each item, if we don't already have a 'bucket' for it, create a new empty one
Add it to the bucket
return the new updated bucket list.
The method returns an object with 3 properties: 16,18 and 20, each containing the objects with that age.

This will work. The output is in different format than one provided by exebook .
Please check and confirm. Here's a fiddle....
** UX Manager
var buckets = [];
for (var item in items) {
var currentAge = items[item].age;
if(!buckets[currentAge]) {
buckets[currentAge] = [];
for (var i in items) {
if (currentAge === items[i].age) {
buckets[currentAge].push(items[i]);
}
}
}
}

var items = [
{name:"Foo", age:16, color:"w"},
{name:"Bar", age:18, color:"b"},
{name:"foo", age:16, color:"w"},
{name:"bar", age:18, color:"w"},
{name:"foobar", age:18, color:"b"},
{name:"barfoo", age:20, color:"w"}
];
var result = [] // THIS IS THE RESULTING ARRAY THAT YOU WANT
function find(age) {
for (var i = 0; i < result.length; i++)
if (result[i].age == age) return i
return -1
}
function append(i, obj) {
result[i].name.push(obj.name)
result[i].color.push(obj.color)
}
for (var i = 0; i < items.length; i++) {
var x = find(items[i].age)
if (x < 0) result.push({ age: items[i].age, name: [items[i].name], color : [items[i].color]})
else append(x, items[i])
}
console.log(result) // PRINT THE RESULT, alternatively you can use alert(result)
The output
[ { age: 16, name: [ 'Foo', 'foo' ], color: [ 'w', 'w' ] },
{ age: 18, name: [ 'Bar', 'bar', 'foobar' ], color: [ 'b', 'w', 'b' ] },
{ age: 20, name: [ 'barfoo' ], color: [ 'w' ] } ]

Develop Reference

JavaScript is the programming language of the Web.

create an array of objects from an object and array - javascript

you want a new object for each iteration for (var i = 0; i < category.length; i++) { var obj = {}; obj [category[i]] = items[i]; newArray.push(obj); }

I guess this should do it; var items = { 0: "foo", 1: "bar", 2: "baz" }, category = [ "type1", "type2", "type3" ], newArray = category.map((e,i) => ({[e]:items[i]})); console.log(newArray)

You could try something like this -> category.forEach(function (e,i) { var obj = {}; obj[e] = items[i]; newArray.push(obj); });

var items = { 0: "foo", 1: "bar", 2: "baz" }, category = [ "type1", "type2", "type3" ]; var reformattedArray = category.map(function(obj, index){ var rObj = {}; rObj[obj] = items[index]; return rObj; }); console.log("reformattedArray", reformattedArray); https://jsfiddle.net/s6ntL2eo/

Related

Converting an array of 3 arrays into 1 big array with object variable

javascript array of object with key

Get all possible options for a matrix in javascript

re building a json from an exciting one nodejs

Split array of objects into new array or objects based on age value

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