I have the following data with me.
var Inputdata = {};
Inputdata.firstName = 'Raul'
Inputdata.lastName = 'Peters'
I want to check if the firstName and lastName (together) is already present in the array of objects. Can someone please let me know how to achieve this.
UserData: [0]
firstName: 'Raul'
lastName: 'Peters'
Id: '4'
[1]
firstName: 'Amil'
lastName: 'Rikia'
Id: '5'
[2]
firstName: 'Riya'
lastName: 'Pillai'
Id: '6'
[3]
firstName: 'Natasha'
lastName: 'Shacke'
Id: '6'
[4]
firstName: 'Eric'
lastName: 'Coles'
Id: '6'
As you can see, Raul Peters is present in the array of objects in one array. I want the output to be true in this case. If Raul and Peters were in different objects, the answer should be false as Raul and Peters are not in the same object. Can anyone please let me know how to achieve this
Just do an Array.some check:
let isPresent = UserData.some(user => user.firstName == 'Raul' && user.lastName == 'Peters')
Use Array.find
arr.find( function(e){
if(e.firstname == 'Raul' && e.lastname == 'Peters')
return e;
});
const inputData = {};
inputData.firstName = 'Raul';
inputData.lastName = 'Peters';
const userData = [
{
firstName: 'Raul',
lastName: 'Peters',
Id: '4'
},
{
firstName: 'Amil',
lastName: 'Rikia',
Id: '5'
},
{
firstName: 'Riya',
lastName: 'Pillai',
Id: '6'
},
{
firstName: 'Natasha',
lastName: 'Shacke',
Id: '6'
},
{
firstName: 'Eric',
lastName: 'Coles',
Id: '6'
}
];
This function receives 2 arguments: the userData array of objects and the inputData object. Then, it uses the Array.prototype.some() method to see if there is at least one entry within the userData array that is an object matching the inputData object.
function alreadyExists(userData, inputData) {
return userData.some(entry => entry['firstName'] === inputData['firstName'] && entry['lastName'] === inputData['lastName']);
};
console.log(alreadyExists(userData, inputData));
If you wanna use underscore or lodash you can use function _.some. Using internal variable you can get needle element.
var needle = false;
var has = _.some(UserData, function(v) {
return (v.firstName===Inputdata.firstName && v.lastName===Inputdata.lastName) ? needle = v : false;
});
console.log(has)
console.log(needle)
Related
I need to make a function that receives 2 parameters, the first one is an array of a list of users that must contain first name, last name and phone numbers, at least 3 of those users must start with the letter "a", the second parameter is a callback. You must process the array and delete all the users whose name starts with the letter "a". Then send the new processed array to the callback. The callback must show in console, the list of all the names, concatenating first and last name.
const users =
[{
name: 'Diego',
lastname: 'Garcia',
phone: '12343'
},
{
name: 'Camilo',
lastname: 'Garcia',
phone: '12343'
}, {
name: 'ana',
lastname: 'Rodriguez',
phone: '02343'
}, {
name: 'anastasia',
lastname: 'Zapata',
phone: '42343'
}, {
name: 'alejandra',
lastname: 'Perez',
phone: '52343'
}];
const operation2 = (list) => {
let x = [];
let callback = {};
callback = list.find(element => element.name.charAt(0) == 'a');
let l = list.indexOf(callback)
let g = list[l];
console.log(g)
if (callback) {
x = list.splice(l, 1)
} return list
}
console.log(operation2(users))
The code that I made does not work, it is not eliminating all the names that begin with "a", it only eliminates the first object of the array.
Array.find only finds the first match, you should probably filter out the elements you don't want:
const result = list.filter(element => element.name.charAt(0) !== 'a');
const users =
[{
name: 'Diego',
lastname: 'Garcia',
phone: '12343'
},
{
name: 'Camilo',
lastname: 'Garcia',
phone: '12343'
}, {
name: 'ana',
lastname: 'Rodriguez',
phone: '02343'
}, {
name: 'anastasia',
lastname: 'Zapata',
phone: '42343'
}, {
name: 'alejandra',
lastname: 'Perez',
phone: '52343'
}];
function func(list, callback) {
let users = list.filter(u => !u.name.toLowerCase().startsWith('a'));
callback(users)
}
func(users, (users) => {
console.log(users)
})
So I am not the best at writing functions so I am having a hard time wrapping a head around this. So I am trying to create a function that traverses through array of objects, and stops once it reads the name that is given it must return the number of the that person.
const array = [{name: 'Ann', phone: '575.580.1400', role: 'Developer'},
{name: 'Ben', phone: '575.641.4041', role: 'Manager'},
{name: 'Clara', phone: '512.717.5690', role: 'Developer'}];
const getNumber = (person, book ) => {
for (var x of book ) {
if( x == person) {
return number;}
return ('Not found');
}
}
I know I am missing how to call in the number, but I just can't think of how to do it.
First you need to access the key inside the object and return ('Not found'); is not in the right place. Secondly use === instead of ==.In your code if the function will return in the fist iteration only. Because if you search for Clara and in the if condition Ann will not be equal to Clara so it will return Not Found and will not iterate the remaining array
const array = [{
name: 'Ann',
phone: '575.580.1400',
role: 'Developer'
},
{
name: 'Ben',
phone: '575.641.4041',
role: 'Manager'
},
{
name: 'Clara',
phone: '512.717.5690',
role: 'Developer'
}
];
const getNumber = (person, book) => {
for (var x of book) {
if (x.name === person) {
return x.phone;
}
}
return ('Not found');
}
console.log(getNumber('Clara', array))
Alternatively you can also use array methods like find or filter
const array = [{
name: 'Ann',
phone: '575.580.1400',
role: 'Developer'
},
{
name: 'Ben',
phone: '575.641.4041',
role: 'Manager'
},
{
name: 'Clara',
phone: '512.717.5690',
role: 'Developer'
}
];
const num = array.find(item => item.name === 'Clara').phone;
console.log(num)
Below code helps to iterate through a JSON object and print the required value. You can use the required conditions in IF and print the desired values accordingly.
var json = [{name: 'Ann', phone: '575.580.1400', role: 'Developer'},
{name: 'Ben', phone: '575.641.4041', role: 'Manager'},
{name: 'Clara', phone: '512.717.5690', role: 'Developer'}];
for (var key in json) {
if (json.hasOwnProperty(key)) {
if(json[key].name=='Ben')
console.log(json[key].phone);
}
}
Try this
I am using some instead of foreach or other loops. some() method executes the callback function once for each element present in the array until it finds the one where callback returns a truthy value.
const getNumber = (person, book ) => {
let pnumber;
book.some((item) => {
if(item.name.toLowerCase()===person.toLowerCase()){
pnumber = item.phone;
return true;
}
})
return pnumber ? pnumber: "Not Found" ;
}
you can call it this way
getNumber('clara',array)
"512.717.5690"
getNumber('ben1',array)
"Not Found"
I'm using angular 2 at the moment.
And I have array of some data
data: MyModel[] = [
{
id: 1,
name: 'Name',
secondName: 'SecondName'
}
Also MyModel is interface:
interface MyModel {
id: number,
name: string,
secondName: string
Let's imagine, that I received data from Back-End(object json):
{
id: 2,
FIRSTname: 'FName',
secondName: 'SecondName'
}
How can I validate, that keys in object are equals to my interface?
For example field "FIRSTname" is incorrect, then I should throw exception or something else.
Maybe there is a better way in typescript, in es6 you can do:
const data = [
{
id: 2,
name: 'FName',
secondName: 'SecondName'
},
{
name: 'foo',
secondName: 'bar'
},
];
const validate = ({id, name, secondName}) => id && name && secondName
const validData = data.filter(validate)
console.log(validData);
Be a ware that if one of the values: id, name, secondName, is null validate will return false.
What if I say that you can define a variable obj implementing the model interface and initialise all its property and then compare the keys of obj with the backend data lets name it respDataObj
Array.prototype.compare = function(testArr) {
if (this.length != testArr.length) return false;
for (var i = 0; i < testArr.length; i++) {
if (this[i].compare) { //To test values in nested arrays
if (!this[i].compare(testArr[i])) return false;
}
else if (this[i] !== testArr[i]) return false;
}
return true;
}
Object.keys(respDataObj).compare(Object.keys(obj))
Compare function courtesy: https://stackoverflow.com/a/6229258/2791802
I've got a votes array with users. Now I would like to remove a user
based on his id.
role: 2
active: 2
about: null
id: 3
email: "test#gmail.com.com"
created_at: "2016-11-08 17:14:16"
function: "functie...."
last_name: "Janssen"
mobile: "6"
pivot: Object
updated_at: "2016-11-08 17:30:20"
Method:
option.votes.$remove($root.user.id);
Obviously this is not working. How do I get this to work?
Try this:
newArray = myArray.filter(function( obj ) {
return obj.id !== 'idToDelete';
});
option.votes = newArray
I have an array of javascript objects that represent users, like so:
[
{ userName: "Michael",
city: "Boston"
},
{ userName: "Thomas",
state: "California",
phone: "555-5555"
},
{ userName: "Kathrine",
phone: "444-4444"
}
]
Some of the objects contain some properties but not others. What I need is a clean way to ensure ALL objects get the same properties. If they don't exist, I want them to have an empty string value, like so:
[
{ userName: "Michael",
city: "Boston",
state: "",
phone: ""
},
{ userName: "Thomas",
city: "",
state: "California",
phone: "555-5555"
},
{ userName: "Kathrine",
city: "",
state: "",
phone: "444-4444"
}
]
Update
I should have been a little more specific. I was looking for an option that would handle this situation dynamically, so I don't have to know the properties ahead of time.
For jQuery specific, the $.extend() option is a good one, but will only work if you know ALL the properties ahead of time.
A few have mentioned that this should probably be a server-side task, and while I normally agree with that, there are two reasons I'm not handling this at the server-side:
1) it will be a smaller JSON object if say 900 of 1000 objects only contain 1 of a possible 9 properties.
2) the "empty" properties need to be added to satisfy a JS utility that could be replaced in the future with something that doesn't care if some properties are missing.
Since you are using jQuery you can abuse $.extend
function Person(options){
return $.extend({
userName:"",
city: "",
state:"",
phone: ""
},options);
}
$.map([{}],Person)
update
Heres a way to have dynamic default properties
function mapDefaults(arr){
var defaultProperties = {}
for(var i =0; i < arr.length; i++){
$.each(arr[i],function(key){
defaultProperties[key] = "";
});
}
function Defaulter(obj){
return $.extend({},defaultProperties,obj);
}
return $.map(arr, Defaulter);
}
mapDefaults([{a:"valA"},{b:"valB"}]);
/* produces:
[{a:"valA",b:""},{a:"",b:"valB"}]
*/
Something you might try is creating a coalescing function:
function coalesceValues(val){
switch(val)
case undefined:
case null:
return '';
break;
default:
return val;
break;
}
}
Or if you wanted to forego customization for simplicity:
function coalesceValues(val){
return val || '';
}
And then apply it when assigning variables:
var city = coalesceValues(obj.city);
This way you don't need to do any crazy breakdown to array and loop or anything, you can apply it to whatever you want, and you can also customize the values you want to coalesce.
Just offering an alternative idea.
The way that is easiest to understand is probably to make a function that accepts an object and uses if statements as existence checks, assigning a default value if it doesn't find it.
function normalize(object) {
if(typeof object.userName === 'undefined') {
object.userName = 'Default Value';
}
if(typeof object.city === 'undefined') {
object.city = 'Default Value';
}
if(typeof object.state === 'undefined') {
object.state = 'Default Value';
}
if(typeof object.phone === 'undefined') {
object.phone = 'Default Value';
}
return object;
}
var userArray = [{},{},{}].map(normalize);
We can also go the constructor route and provide default values on object creation.
function User (data) {
this.userName = data.userName || 'Default Value';
this.city = data.city || 'Default Value';
this.state = data.state || 'Default Value';
this.phone = data.phone || 'Default Value';
return this;
}
var userArray = [{},{},{}].map(function(o){
return new User(o);
});
Of course this depends on one specific type of data and won't extend to other properties and isn't very DRY, but as I said, this is probably the easiest to understand from a beginner's standpoint.
var list = [
{ userName: "Michael",
city: "Boston"
},
{ userName: "Thomas",
state: "California",
phone: "555-5555"
},
{ userName: "Kathrine",
phone: "444-4444"
}
];
for(var i = 0; i < list.length; i++){
if(list[i].state === undefined)
list[i].state = "";
if(list[i].phone === undefined)
list[i].phone = "";
};
console.log(list);
http://jsfiddle.net/g5XPk/1/
This should probably be a server-side task, but..
If you know all the possible properties ahead of time, you could do this:
http://jsfiddle.net/BMau9/
var properties = ['userName', 'city', 'state', 'phone'];
var data = [{
userName: "Michael",
city: "Boston"
}, {
userName: "Thomas",
state: "California",
phone: "555-5555"
}, {
userName: "Kathrine",
phone: "444-4444"
}];
for (var i in data) {
for (var j in properties) {
data[i][properties[j]] = data[i][properties[j]] || '';
}
}
Fiddle
This function stores unique object keys in an array and so you can run your array of objects through it and then use one of the other supplied answers to add the keys to the objects if they do not exist:
function uniqueKeys(){
var keys=[];
function getUniqueKeys(){
return keys
}
function addObject(obj){
for (var k in obj){
keys = _.union(keys,[k]);
}
}
return {
addObj: addObject,
getKeys: getUniqueKeys
}
}
Usage:
var objArr = [{ userName: "Michael", city: "Boston" },
{ userName: "Thomas", state: "California", phone: "555-5555"},
{ userName: "Kathrine",phone: "444-4444" }];
var uniq = new uniqueKeys();
_.each(objArr, function(v){
uniq.addObj(v)
});
var keys = uniq.getKeys();
alert(keys);
vanilla js
let A = [
{
userName: "Michael",
city: "Boston",
},
{
userName: "Thomas",
state: "California",
phone: "555-5555",
},
{
userName: "Kathrine",
phone: "444-4444",
},
];
// set-difference
const diff = (a,b) => new Set([...a].filter((x) => !b.has(x)));
// all keys
const K = new Set(arr.map(o => Object.keys(o)).flat());
// add missing keys and default vals
A.forEach((e,i) => diff(K, new Set(Object.keys(e))).forEach(k => A[i][k] = ""));