Why the array returning empty spaces

Why the array returning empty spaces - javascript

It should be returning 9-12,1-4,5-8,9-11 but instead it's returning 9-12,1-4,5-8,9-11,,,,
var arr = [{
Sanju: '9-12'
}, {
Sanju: '1-4'
}, {
Sanju: '5-8'
}, {
Sanju: '9-11'
},
{
IRONMAN: '9-12'
}, {
VIVEGAM: '1-4'
}, {
VIVEGAM: '5-8'
}, {
VIVEGAM: '9-11'
}
];
var b = Array.from(arr, x => x.Sanju);
document.write(b);
document.write(Array.isArray(b));

Since not all values in arr contains Sanju, some of the values will give you undefined when you return x.Sanju You can use filter to remove those like
var arr = [{Sanju: '9-12'},{Sanju: '1-4'}, {Sanju: '5-8'},{Sanju: '9-11'},
{IRONMAN: '9-12'},{VIVEGAM: '1-4'}, {VIVEGAM: '5-8'},{VIVEGAM: '9-11'}
];
var b= Array.from(arr, x => x.Sanju).filter(Boolean);
document.write(b);
document.write(Array.isArray(b));
Check Removing undefined values from Array for more details on how .filter(Boolean) works

It should be returning 9-12,1-4,5-8,9-11 but instead it's returning 9-12,1-4,5-8,9-11,,,,
Coz there is no Sanju property on some of the objects. You should first filter you array and then do the rest
var arr = [{
Sanju: '9-12'
}, {
Sanju: '1-4'
}, {
Sanju: '5-8'
}, {
Sanju: '9-11'
},
{
IRONMAN: '9-12'
}, {
VIVEGAM: '1-4'
}, {
VIVEGAM: '5-8'
}, {
VIVEGAM: '9-11'
}
];
var o = arr.filter(i=> i.Sanju);
var b = Array.from(o, x => x.Sanju);
document.write(b);
document.write(Array.isArray(b));

Related

Remove duplicate objects based on the same key from array and add their value to the object that is left

Consider the following array of objects in javascript
const array = [
{ 10205: 2 },
{ 10207: 3 },
{ 10205: 2 },
{ 10207: 1 }
]
I would like to have it converted to
array = [
{ 10205: 4 },
{ 10207: 4 }
]

const array = [{ 10205: 2 }, { 10207: 3 }, { 10205: 2 }, { 10207: 1 }];
const newArray = [];
array.forEach((element) => {
const elementKey = Object.keys(element)[0];
const foundIndex = newArray.findIndex((_) => Object.keys(_)[0] === elementKey);
if (foundIndex >= 0) {
newArray[foundIndex] =
{[elementKey]: newArray[foundIndex][elementKey] + element[elementKey]};
} else newArray.push(element);
});
console.log(newArray)

Please use reduce function.
const array = [
{ 10205: 2 },
{ 10207: 3 },
{ 10205: 2 },
{ 10207: 1 }
]
console.log(Object.values(array.reduce((acc, el)=>{
Object.keys(el).map((key)=>{
acc[key] = {
[key]: (acc?.[key]?.[key] ?? 0) + el[key],
}
})
return acc;
}, {})));

JavaScript Array attribute change

I have an array like this.
let arr = [
{
"ABBRIVATION":"ISB",
"name":"ISLAMABAD",
},
{
"ABBRIVATION":"RAW",
"name":"PINDI",
},
{
"ABBRIVATION":"SWB",
"name":"SWABI",
},
{
"ABBRIVATION":"AQ",
"name":"AQEEL",
},
]
I want to change it to like this
let me explain it a little. I want to assign the abbreviation directly to the name and the iterate through that array
let outout = [
{
"ISB":"ISLAMABAD"
},
{
"RAW":"ISLAMABAD"
},
{
"SWB":"SWABI"
},
{
"AQ":"AQEEL"
},
]
that is what I tried
let k = arr.map((item) => {
return item.ABB = item.name
})
console.log(k)
and here is the output
[ 'ISLAMABAD', 'PINDI', 'SWABI', 'AQEEL' ]

Here you go, use array map, simples
let arr = [
{
"ABBRIVATION":"ISB",
"name":"ISLAMABAD",
},
{
"ABBRIVATION":"RAW",
"name":"PINDI",
},
{
"ABBRIVATION":"SWB",
"name":"SWABI",
},
{
"ABBRIVATION":"AQ",
"name":"AQEEL",
},
]
let outout = arr.map(({ABBRIVATION, name}) => ({[ABBRIVATION]: name}));
console.log(outout);

Nothing more than a simple Array.prototype.map() needed.
let arr = [
{
ABBRIVATION: "ISB",
name: "ISLAMABAD",
},
{
ABBRIVATION: "RAW",
name: "PINDI",
},
{
ABBRIVATION: "SWB",
name: "SWABI",
},
{
ABBRIVATION: "AQ",
name: "AQEEL",
},
];
const result = arr.map(e => ({ [e.ABBRIVATION]: e.name }));
console.log(result);

map over the array of objects (map returns a new array) and assign the name to a new key defined by the abbreviation.
You code works the way it does because item.ABB is undefined, but you're also assigning item.name to it which does get returned, so you just get an array of names returned.
const arr=[{ABBRIVATION:"ISB",name:"ISLAMABAD"},{ABBRIVATION:"RAW",name:"PINDI"},{ABBRIVATION:"SWB",name:"SWABI"},{ABBRIVATION:"AQ",name:"AQEEL"}];
const out = arr.map(obj => {
return { [obj.ABBRIVATION]: obj.name };
});
console.log(out);

Hi I have seen people answer, but most of them use the map function, I provide some other solutions, hoping to expand the thinking
Use forEach function
const datas = [
{
"ABBRIVATION":"ISB",
"name":"ISLAMABAD",
},
{
"ABBRIVATION":"RAW",
"name":"PINDI",
},
{
"ABBRIVATION":"SWB",
"name":"SWABI",
},
{
"ABBRIVATION":"AQ",
"name":"AQEEL",
}
];
datas.forEach((obj, i, arr) => {
const{'ABBRIVATION':k, 'name':v} = obj;
arr[i] = {[k]:v};
});
console.log(datas);
Use flatMap function
const datas = [
{
"ABBRIVATION":"ISB",
"name":"ISLAMABAD",
},
{
"ABBRIVATION":"RAW",
"name":"PINDI",
},
{
"ABBRIVATION":"SWB",
"name":"SWABI",
},
{
"ABBRIVATION":"AQ",
"name":"AQEEL",
}
];
const result = datas.flatMap(obj => {
const {'ABBRIVATION':k, 'name':v} = obj;
return {[k]:v};
});
console.log(result);

this is how you suppose to do it.
arr.reduce((d, c)=>([...d, {[c.ABBRIVATION]: c.name}]),[])
let arr = [
{
"ABBRIVATION":"ISB",
"name":"ISLAMABAD",
},
{
"ABBRIVATION":"RAW",
"name":"PINDI",
},
{
"ABBRIVATION":"SWB",
"name":"SWABI",
},
{
"ABBRIVATION":"AQ",
"name":"AQEEL",
},
]
console.log(arr.reduce((data, current)=>([...data, {[current.ABBRIVATION]: current.name}]),[]))

how to change value of all nodes of json array

I have a json array with different key values and need to add a ServerUrl to the beginning of all node values using a loop without writing multiple statements to do that by using javascript:
"Urls": [
{ "getCar": "/getAllCars" },
{ "getPerson": "/getAllPersons" },
{ "getBook": "/getAllBooks" }
],
"ServerUrl": "http://192.168.1.1:3000"
The expected result must be:
"Urls": [
{ "getCar": "http://192.168.1.1:3000/getAllCars" },
{ "getPerson": "http://192.168.1.1:3000/getAllPersons" },
{ "getBook": "http://192.168.1.1:3000/getAllBooks" }
],
Any advice would be appreciated.

You can use map to map your objects to new objects. Those objects have a single property, which you can get with Object.keys. The new object can get that same property name using the computed property name feature:
var obj = {
"Urls": [
{ "getCar": "/getAllCars" },
{ "getPerson": "/getAllPersons" },
{ "getBook": "/getAllBooks" }
],
"ServerUrl": "http://192.168.1.1:3000"
};
var urls = obj.Urls.map(o => Object.keys(o).map(k => ({ [k]: obj.ServerUrl + o[k] }))[0]);
console.log(urls);

const jsonVal = {
"Urls": [
{ "getCar": "/getAllCars" },
{ "getPerson": "/getAllPersons" },
{ "getBook": "/getAllBooks" }
],
"ServerUrl": "http://192.168.1.1:3000"
}
const result = jsonVal.Urls.map(val =>
Object.keys(val).reduce((resultObj, endpointKey) => {
resultObj[endpointKey] = `${jsonVal.ServerUrl}${val[endpointKey]}`;
return resultObj;
}, {})
);

Try (where your data are in d)
d.Urls.forEach( (x,i,a,k=Object.keys(x)[0]) => x[k] = d.ServerUrl + x[k]);
let d = {
"Urls": [
{ "getCar": "/GetAllGroupCustomers" },
{ "getPerson": "/getAllItems" },
{ "getBook": "/GetAllCustomers" }
],
"ServerUrl": "http://192.168.1.1:3000"
}
d.Urls.forEach( (x,i,a,k=Object.keys(x)[0]) => x[k] = d.ServerUrl + x[k]);
console.log(d);

A version that modifies your own object
var obj = {
"Urls": [
{ "getCar": "/getAllCars" },
{ "getPerson": "/getAllPersons" },
{ "getBook": "/getAllBooks" }
],
"ServerUrl": "http://192.168.1.1:3000"
};
obj.Urls.forEach(o => o[Object.keys(o)[0]] = `${obj.ServerUrl}${o[Object.keys(o)[0]]}`);
console.log(obj);

Javascript Fill array with missing object and value

I have an array like bellow each index contains different set of objects,I want to create an uniformal data where object missing in each index will with Value:0 ,
var d = [
[
{axis:"Email",value:59,id:1},
{axis:"Social Networks",value:56,id:2},
],
[
{axis:"Sending Money",value:18,id:6},
{axis:"Other",value:15,id:7},
]
];
how can I get an array like bellow using above above array
var d = [
[
{axis:"Email",value:59,id:1},
{axis:"Social Networks",value:56,id:2},
{axis:"Sending Money",value:0,id:6},
{axis:"Other",value:0,id:7},
],
[
{axis:"Email",value:0,id:1},
{axis:"Social Networks",value:0,id:2},
{axis:"Sending Money",value:18,id:6},
{axis:"Other",value:15,id:7},
]
];

There are two functions:
getAllEntries that find all objects and stores them into a variable accEntries. Then accEntries is used to search for all occurrences in a sub-array of d. This whole process is done in checkArray.
checkArray is used to fetch all found and not-found entries in d. Both Arrays (found and not-found) are then used to build a new sub-array that contains either found entries with certain values and/or not-found entries with values of 0.
Hope this helps:
var d = [
[
{
axis: 'Email',
value: 59,
id: 1
},
{
axis: 'Social Networks',
value: 56,
id: 2
},
],
[
{
axis: 'Sending Money',
value: 18,
id: 6
},
{
axis: 'Other',
value: 15,
id: 7
},
]
];
function getAllEntries(array) {
var uniqueEntries = [];
array.forEach(function (subarray) {
subarray.forEach(function (obj) {
if (uniqueEntries.indexOf(obj) === - 1) uniqueEntries.push(obj);
});
});
return uniqueEntries;
}
function checkArray(array, acceptedEntries) {
var result = [];
array.forEach(function (subArray) {
var subResult = [];
var foundEntries = [];
subArray.forEach(function (obj) {
if (foundEntries.indexOf(obj.axis) === - 1) foundEntries.push(obj.axis);
});
var notFound = acceptedEntries.filter(function (accepted) {
return foundEntries.indexOf(accepted.axis) === - 1;
});
foundEntries.forEach(function (found) {
subArray.forEach(function (obj) {
if (obj.axis === found) subResult.push(obj);
});
});
notFound.forEach(function (notfound, index) {
subResult.push({
axis: notfound.axis,
value: 0,
id: notfound.id
});
});
result.push(subResult);
});
return result;
}
var accEntries = getAllEntries(d);
var result = checkArray(d, accEntries);
console.log(result);

You can loop over the array to find all the unique objects and then again loop over to push the values that are not present comparing with the array of objects of unique keys.
You can use ES6 syntax to find if an object with an attribute is present like uniKeys.findIndex(obj => obj.axis === val.axis); and the to push with a zero value use the spread syntax like d[index].push({...val, value: 0});
Below is the snippet for the implementation
var d = [
[
{axis:"Email",value:59,id:1},
{axis:"Social Networks",value:56,id:2},
],
[
{axis:"Sending Money",value:18,id:6},
{axis:"Other",value:15,id:7},
{axis:"Social Networks",value:89,id:2},
]
];
var uniKeys = [];
$.each(d, function(index, item) {
$.each(item, function(idx, val){
const pos = uniKeys.findIndex(obj => obj.axis === val.axis);
if(pos == - 1) {
uniKeys.push(val);
}
})
})
$.each(d, function(index, item) {
var temp = [];
$.each(uniKeys, function(idx, val){
const pos = item.findIndex(obj => obj.axis === val.axis);
if(pos == - 1) {
d[index].push({...val, value: 0});
}
})
})
console.log(d);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

How about a short shallowCopy function (Object.assign is not available in IE) and otherwise less than 10 new lines of code?
var d = [
[
{axis:"Email",value:59,id:1},
{axis:"Social Networks",value:56,id:2}
],
[
{axis:"Sending Money",value:18,id:6},
{axis:"Other",value:15,id:7}
]
];
var newD_0 = [shallowCopy(d[0][0]), shallowCopy(d[0][1]), shallowCopy(d[1][0]), shallowCopy(d[1][1])];
var newD_1 = [shallowCopy(d[0][0]), shallowCopy(d[0][1]), shallowCopy(d[1][0]), shallowCopy(d[1][1])];
newD_0[2].id = 0;
newD_0[3].id = 0;
newD_1[0].id = 0;
newD_1[1].id = 0;
d = [newD_0, newD_1];
function shallowCopy(obj) {
var copy = {};
for (var key in obj) {
if (obj.hasOwnProperty(key)) {
copy[key] = obj[key];
}
}
return copy;
}
console.log(JSON.stringify(d));
RESULT:
[
[
{
"axis":"Email",
"value":59,
"id":1
},
{
"axis":"Social Networks",
"value":56,
"id":2
},
{
"axis":"Sending Money",
"value":18,
"id":0
},
{
"axis":"Other",
"value":15,
"id":0
}
],
[
{
"axis":"Email",
"value":59,
"id":0
},
{
"axis":"Social Networks",
"value":56,
"id":0
},
{
"axis":"Sending Money",
"value":18,
"id":6
},
{
"axis":"Other",
"value":15,
"id":7
}
]
]

Deep merging nested arrays

I have to merge 2 arrays with key value as follows:
array1 = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"test2"},{id:"yz", data:"test3"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"}]}]
with
array2 = [
{id:"456", data:[{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}]
to produce something like
merged = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"},{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}]
I've been trying this out for quite some time and can't get a solution that meets the scenario. Most of the solutions just do blind merging, not based on the id value. Tried using lodash mergeWith but didn't get the output needed. A Ramda solution is also acceptable.
Thanks,

This links could be helpful to you merge two arrays.
In this code snippet, i have tried to find the common objects between set1 and set2,if there are any i'm finding the unique properties and changing their content and also non existant properties in object2 and pushing it to object1
Check the following snippet.
var arr1 = [{
id: "123",
data: [{
id: "234",
data: "hello"
}, {
id: "345",
data: "there"
}, {
id: "xyz",
data: "yo"
}]
}, {
id: "456",
data: [{
id: "34",
data: "test"
}, {
id: "45",
data: "test2"
}, {
id: "yz",
data: "test3"
}]
}, {
id: "789",
data: [{
id: "23",
data: "aaa"
}, {
id: "34",
data: "bbb"
}, {
id: "xy",
data: "ccc"
}]
}]
var arr2 = [{
id: "456",
data: [{
id: "45",
data: "changed"
}, {
id: "yz",
data: "data"
}]
}, {
id: "789",
data: [{
id: "456",
data: "appended data"
}]
}, {
id: "890",
data: [{
id: "456",
data: "new data"
}]
}]
var arr3 = [];
for (var i in arr1) {
var shared = false;
for (var j in arr2)
if (arr2[j].id == arr1[i].id) {
shared = true;
// arr1[i].data.concat(arr2[j].data);
var set1 = pushproperties(arr1[i].data, arr2[j].data);
arr1[i].data = set1;
arr3.push(arr1[i]);
break;
}
if (!shared) {
arr3.push(arr1[i]);
arr3.push(arr2[j]);
}
}
function pushproperties(set1, set2) {
var filtered = false;
set2.forEach(function(item) {
filtered = set1.every(function(element) {
return element.id != item.id;
});
if (filtered) {
set1.push(item);
}
});
set1.forEach(function(item) {
set2.forEach(function(element) {
if (item.id == element.id) {
item.data = element.data;
}
});
});
return set1;
}
console.log(arr3);
Hope this helps

This a function the merges 2 arrays recursively using Array.prototype.reduce(). If it encounters items with the same id, and they have a data prop, which is an array, it merges them using the logic. If data is not an array, it's overridden by the last item instead.
function mergeArraysDeep(arr1, arr2) {
var unique = arr1.concat(arr2).reduce(function(hash, item) {
var current = hash[item.id];
if(!current) {
hash[item.id] = item;
} else if (Array.isArray(current.data)) {
current.data = mergeArraysDeep(current.data, item.data);
} else {
current.data = item.data;
}
return hash;
}, {});
return Object.keys(unique).map(function(key) {
return unique[key];
});
}
var array1 = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"test2"},{id:"yz", data:"test3"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"}]}
];
var array2 = [
{id:"456", data:[{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}
];
var result = mergeArraysDeep(array1, array2)
console.log(result);
ES6 version that uses Map, Map.prototype.values(), and array spread:
const mergeArraysDeep = (arr1, arr2) => {
return [...arr1.concat(arr2).reduce((hash, item) => {
const current = hash.get(item.id);
if(!current) {
hash.set(item.id, item);
} else if (Array.isArray(current.data)) {
current.data = mergeArraysDeep(current.data, item.data);
} else {
current.data = item.data;
}
return hash;
}, new Map()).values()];
}
const array1 = [
{id:"123", data:[{id:"234",data:"hello"},{id:"345",data:"there"},{id:"xyz", data:"yo"}]},
{id:"456", data:[{id:"34",data:"test"},{id:"45",data:"test2"},{id:"yz", data:"test3"}]},
{id:"789", data:[{id:"23",data:"aaa"},{id:"34",data:"bbb"},{id:"xy", data:"ccc"}]}
];
const array2 = [
{id:"456", data:[{id:"45",data:"changed"},{id:"yz", data:"data"}]},
{id:"789", data:[{id:"456",data:"appended data"}]},
{id:"890", data:[{id:"456",data:"new data"}]}
];
const result = mergeArraysDeep(array1, array2)
console.log(result);

Finally this is what worked for me. Thanks to #Geeky for showing the way:
function mergeArrays(arr1, arr2) {
var arr3, arrIdx = [];
if (!arr1 || arr1.length ==0) return arr2
for (var i in arr1) {
var shared = false;
for (var j in arr2)
if (arr2[j].id == arr1[i].id) {
shared = true;
joined = _.mergeWith({},arr1[i],arr2[j], function (a,b) {
if (_.isArray(a)) return b.concat(a)})
arr3.push(joined);
break;
}
if (!shared) {
arr3.push(arr1[i]);
}
}
for (var k in arr2) {
if (arrIdx[k] !=k) arr3.push(arr2[k])
}
return arr3
}

Develop Reference

JavaScript is the programming language of the Web.

Why the array returning empty spaces - javascript

Related

Remove duplicate objects based on the same key from array and add their value to the object that is left

JavaScript Array attribute change

how to change value of all nodes of json array

Javascript Fill array with missing object and value

Deep merging nested arrays

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