How to merge the two array of objects in one array,the given array of objects like below.
var arr1=[{key:2000,value:100},{key:2001,value:200},{key:3000,value:300}]
var arr2=[{key1:2000,value1:100},{key1:2001,value1:200},{key1:3000,value1:300}]
Expected output:
[
{
"key": 2000,
"value": 100,
"child": [
{
"key1": 2000,
"value1": 100
}
]
},
{
"key": 2001,
"value": 200,
"child": [
{
"key1": 2001,
"value1": 200
}
]
},
{
"key": 3000,
"value": 300,
"child": [
{
"key1": 3000,
"value1": 300
}
]
}
]
UPDATED: As some other folks have mentioned, you can loop through the first array and assign the corresponding element of the second array to the child property of the appropriate object in the first array, or you can use Array.prototype.map
for example:
var newArray = arr1.map(function(cur, idx) {
cur.child = [arr2[idx]];
return cur;
});
It should be noted that this (and the other solutions mentioned) depend on both arrays containing the same keys, and that they are both sorted by object key.
If you're not sure that the arrays will be sorted by key, you will have to do some preprocessing. You can either sort both arrays first (this is still fragile because there are no guarantees that the keys in both arrays are the same), or do something like:
var secondGroupByKey = {};
for (var i=0; i<arr2.length; i++) {
secondGroupByKey[arr2[i].key1] = arr2[i];
}
and then you can safely say:
var key;
for (var j=0; j<arr1.length; j++) {
key = arr1[j].key;
if (secondGroupByKey[key] !== undefined) {
arr1[j].child = [secondGroupByKey[key]];
}
}
This approach is safer than relying on the order of the arrays, but it comes with the cost of iterating over both arrays instead of just one. You also might want to throw an exception or bail out another way if you find a key in arr1 that's not present in arr2.
Loop through the first array and and assign the corresponding value from the second array to child of each object of the first array.
for(var i = 0;i<arr1.length;i++){
arr1[i].child=[arr2[i]];
}
arr2.forEach(function( obj, i ) {
arr1[ i ].child = [ obj ];
});
If I understood correctly you need to put the n-th element of array B as a 'child' property of the object with the same index on array A; here's my attempt:
function addChildren(master, child){
return master.map(function(elem, i){
elem.child = elem.child || [];
elem.child.push(child[i]);
return elem;
});
};
JSFiddle demo.
Related
I want to loop through 600+ array items in an object and find one particular item based on certain criteria. The array in the object is called "operations" and its items are arrays themselves.
My goal is to get the index of operation's array item which has the deeply nested string "Go".
In the sample below this would be the first element. My problem is that I can check if an array element contains "call" and "draw" but I don't know how to test for the nested dictionary "foobar". I only have basic JavaScript available, no special libraries.
let json = {
"head": {},
"operations": [
[
"call",
"w40",
"draw",
{
"parent": "w39",
"style": [
"PUSH"
],
"index": 0,
"text": "Modify"
}
],
[
"call",
"w83.gc",
"draw",
{
"foobar": [
["beginPath"],
[
"rect",
0,
0,
245,
80
],
["fill"],
[
"fillText",
"Go",
123,
24
],
[
"drawImage",
"rwt-resources/c8af.png",
]
]
}
],
[
"create",
"w39",
"rwt.widgets.Menu",
{
"parent": "w35",
"style": [
"POP_UP"
]
}
],
[
"call",
"w39",
"draw",
{
"parent": "w35",
"style": [
"POP_UP"
]
}
]
]
};
let index = "";
let operationList = json.operations;
for (i = 0; i < operationList.length; i++) {
if (operationList[i].includes('call') && operationList[i].includes('draw')) //missing another check if the dictionary "foobar" exists in this element )
{
index = i;
}
}
document.write(index)
I'll preface by saying that this data structure is going to be tough to manage in general. I would suggest a scheme for where an operation is an object with well defined properties, rather than just an "array of stuff".
That said, you can use recursion to search the array.
If any value in the array is another array, continue with the next level of recursion
If any value is an object, search its values
const isPlainObject = require('is-plain-object');
const containsTerm = (value, term) => {
// if value is an object, search its values
if (isPlainObject(value)) {
value = Object.values(value);
}
// if value is an array, search within it
if (Array.isArray(value)) {
return value.find((element) => {
return containsTerm(element, term);
});
}
// otherwise, value is a primitive, so check if it matches
return value === term;
};
const index = object.operations.findIndex((operation) => {
return containsTerm(operation, 'Go');
});
I need to get a list of all the key names in the following JSON object:
var myJSON = [
{
"Employees_Name": "Bill Sanders",
"Work_plan_during_my_absence": "Work from home",
"Assigned To-Manager Approval": [
"mymanager#gmail.com"
],
"AbsenceVacation_Summary": [
{
"Computed_Leave_Days": 2,
"From_Date": "2018-08-20",
"To_Date": "2018-08-21",
"Id": "Shccbcc230_a30f_11e8_9afa_25436d674c51"
}
],
"Leave_Type": "Work from Home",
"Reporting_Manager": "My Manager",
"Total_Days": 2,
}
]
When I use the Object.keys method, it retrieves only the top level key names:
var keys_arr = Object.keys(myJSON[0]);
console.log(keys_arr);
The result is an array:
"[ 'Employees_Name', 'Work_plan_during_my_absence', 'Assigned To-Manager
Approval', 'AbsenceVacation_Summary', 'Leave_Type', 'Reporting_Manager',
'Total_Days']"
The key names that are missing are the ones inside of 'AbsenceVacation_Summary'.
I think what I need to do is loop through the array of names returned and see if the value is an object or an array...but I don't know how to do this. Please advise.
You're right you need to walk your object structure recursively to discover nested objects and collects their keys:
function collectKeys(inputObject, outputKeys) {
if (Array.isArray(inputObject)) {
for(let i = 0; i < inputObject.length; i++) {
collectKeys(inputObject[i], outputKeys);
}
} else if (typeof inputObject === 'object') {
Object.keys(inputObject).forEach(function(key) {
outputKeys.push(key);
collectKeys(outputKeys[key], outputKeys);
});
}
}
var collectedKeys = [];
collectKeys(myJSON, collectedKeys);
Working fiddle here
Result will show in console
References
javascript typeof
javascript Array.isArray
javascript Array.forEach
I have 2 array objects in Angular JS that I wish to merge (overlap/combine) the matching ones.
For example, the Array 1 is like this:
[
{"id":1,"name":"Adam"},
{"id":2,"name":"Smith"},
{"id":3,"name":"Eve"},
{"id":4,"name":"Gary"},
]
Array 2 is like this:
[
{"id":1,"name":"Adam", "checked":true},
{"id":3,"name":"Eve", "checked":true},
]
I want the resulting array after merging to become this:
[
{"id":1,"name":"Adam", "checked":true},
{"id":2,"name":"Smith"},
{"id":3,"name":"Eve", "checked":true},
{"id":4,"name":"Gary"},
]
Is that possible? I have tried angular's array_merge and array_extend like this:
angular.merge([], $scope.array1, $scope.array2);
angular.extend([], $scope.array1, $scope.array2);
But the above method overlap the first 2 objects in array and doesn't merge them based on matching data. Is having a foreach loop the only solution for this?
Can someone guide me here please?
Not sure if this find of merge is supported by AngularJS. I've made a snippet which does exactly the same:
function merge(array1, array2) {
var ids = [];
var merge_obj = [];
array1.map(function(ele) {
if (!(ids.indexOf(ele.id) > -1)) {
ids.push(ele.id);
merge_obj.push(ele);
}
});
array2.map(function(ele) {
var index = ids.indexOf(ele.id);
if (!( index > -1)) {
ids.push(ele.id);
merge_obj.push(ele);
}else{
merge_obj[index] = ele;
}
});
console.log(merge_obj);
}
var array1 = [{
"id": 1,
"name": "Adam"
}, {
"id": 2,
"name": "Smith"
}, {
"id": 3,
"name": "Eve"
}, {
"id": 4,
"name": "Gary"
}, ]
var array2 = [{
"id": 1,
"name": "Adam",
"checked": true
}, {
"id": 3,
"name": "Eve",
"checked": true
}, ];
merge(array1, array2);
Genuinely, extend in Angular works with object instead of array. But we can do small trick in your case. Here is another solution.
// a1, a2 is your arrays
// This is to convert array to object with key is id and value is the array item itself
var a1_ = a1.reduce(function(obj, value) {
obj[value.id] = value;
return obj;
}, {});
var a2_ = a2.reduce(function(obj, value) {
obj[value.id] = value;
return obj;
}, {});
// Then use extend with those two converted objects
var result = angular.extend([], a1_, a2_).splice(1)
Notes:
For compatibility, reduce may not work.
The after array will replace the previous one. This is because of implementation of extend in Angular.
Given a JSON object such as this:
{
"something": {
"terms": [
{
"span": [
15,
16
],
"value": ":",
"label": "separator"
},
{
"span": [
16,
20
],
"value": "12.5",
"label": "number"
}
],
"span": [
15,
20
],
"weight": 0.005,
"value": ":12.5"
}
}
I asked a question about parsing the object out where label: number here:
JSON/Javascript: return which array object contains a certain property
I got a sufficient answer there (use filter()), but now need to know the original index of the object.
This issue seems to have the answer, but I simply don't know enough about javascript to translate it into something useful for my particular problem.
The following code successfully returns the object. Now I need to modify this to return the original index of the object:
var numberValue, list = parsed.something.terms.filter(function(a){
return a.label==='number';
});
numberValue = list.length ? list[0].value : -1;
This needs to be a pure javascript solution, no external libraries, etc.
I don't think you can modify the filter solution as within the filter you've lost the indexes.
The solution you've linked to uses the angular external library.
So here is a pure JS solution:
var numberValue = parsed.something.terms
.map(function(d){ return d['label']; })
.indexOf('number');
Array.prototype.indexOf()
Array.prototype.map()
Use forEach and collect the indices of objects that satisfy the a.label==='number' predicate :
var target = parsed.something.terms;
var list = [];
target.forEach(function(element, index){
if (element.label==='number') {
list.push(index)
};
});
var numberValue = list.length ? target[list[0]].value : -1;
console.log(list); // [1]
console.log(numberValue); // 12.5
I got stuck trying to retrive array items. So here is the deal. I have a two dimentional array which has value and key so example of my data is:
[
Object { css="SS", title="Apple"},
Object { css="SS", title="Orange"},
Object { css="SS", title="Banana"}
]
I want to see if an object exists in the array above. And I have no idea why its not working, here is my code to find the object:
jQuery.inArray("Apple", fruits["title"]); //this returns -1 why?
Any ideas how to search two dimensional array?
This is not a 2D array, this is an array of objects, so this should work:
for (var i = 0; i < array.length; i++) {
console.log(array[i].title); //Log the title of each object.
if (array[i].title == "Apple") {
console.log("Found apple!");
}
}
Also, objects are key/val pairs, denoted by key : val, not key = val. Your array has syntax errors and shouldn't run.
To be pedantic, you have an array of objects, not a 2d array. Also your syntax for the object parameters is incorrect.
You can use filter() on the array to find the values:
var array = [
{ css: "SS", title: "Apple"},
{ css: "SS", title: "Orange"},
{ css: "SS", title: "Banana"}
];
var matches = array.filter(function (obj) { return obj.title == "Apple" });
if (matches.length) {
// Apple was in the array...
}
If you have an object like this
var peoples = [
{ "name": "bob", "dinner": "pizza" },
{ "name": "john", "dinner": "sushi" },
{ "name": "larry", "dinner": "hummus" }
];
Ignore what's below. Use the filter method!
peoples.filter(function (person) { return person.dinner == "sushi" });
// => [{ "name": "john", "dinner": "sushi" }]
You can search for people who have "dinner": "sushi" using a map
peoples.map(function (person) {
if (person.dinner == "sushi") {
return person
} else {
return null
}
}); // => [null, { "name": "john", "dinner": "sushi" }, null]
or a reduce
peoples.reduce(function (sushiPeople, person) {
if (person.dinner == "sushi") {
return sushiPeople.concat(person);
} else {
return sushiPeople
}
}, []); // => [{ "name": "john", "dinner": "sushi" }]
I'm sure you are able to generalize this to arbitrary keys and values!
fruits probably is a array, fruits["title"] therefor doesn't exist.
You might want to transform your data:
var fruitTitles = fruits.map(function(f) { return f.title; });
jQuery.inArray("Apple", fruitTitles);
From the jQuery docs:
jQuery.inArray( value, array [, fromIndex ] )
I've never used this method, but a quick guess:
var hasIt = jQuery.inArray({css:"SS",title:"Apple"}, myArray);
As the $.inArray() documentation explains, the first argument to the function is the value to search for. Your array does not have any elements that are equal to the string "Apple" that you have supplied in the first argument because none of your array elements are strings (they're all objects).
The second argument to $.inArray() is supposed to be the array itself, but (assuming fruits is the array you show) fruits["title"] is undefined because your array has no property called "title", only the objects in the array have that property.
Try this instead:
var index = $.inArray("Apple", $.map(fruits, function(el) { return el.title; }));
try this code
var fruits = [
{ css:"SS", title:"Apple"},
{ css:"SS", title:"Orange"},
{ css:"SS", title:"Banana"}
];
jQuery.grep(fruits,function(fruit){return fruit.title == 'Apple'});