I have two arrays, I want these two to be combined and duplicate items are not lit and only new items are added and I see the combined array in the console I also want to see the duplicate item in the list on the console I mean, I need two outputs, one to tell me what a duplicate is, and one to show me a new array of combinations of two arrays without duplicates. I wrote this code but it does not work properly Thanks for guiding me
Expected output:
newContact : [
{
"id": 1,
"name": "Oliver"
},
{
"id": 2,
"name": "Liam"
}
{
"id": 3,
"name": "James"
}
{
"id": 4,
"name": "Lucas"
}
]
duplicateContacts: Oliver
let array1 = [
{ id: 1, name: "Oliver" },
{ id: 2, name: "Liam" },
];
let array2 = [
{ id: 1, name: "Oliver" },
{ id: 3, name: "James" },
{ id: 4, name: "Lucas" },
];
let newContact = array1.filter((item) => item.id !== array2.id);
console.log("newContact :", newContact);
console.log("duplicateContacts:");Guess duplicate meaning the same id, add array entries to a map to find duplicates, and the map contains unique items
const array1 = [
{ id: 1, name: "Oliver" },
{ id: 2, name: "Liam" },
];
const array2 = [
{ id: 1, name: "Oliver" },
{ id: 3, name: "James" },
{ id: 4, name: "Lucas" },
];
const duplicates = [];
const map = new Map();
const fill = (array) => array.forEach(item => {
if (map.has(item.id)) {
duplicates.push(item);
} else {
map.set(item.id, item);
}
});
fill(array1);
fill(array2);
console.log(duplicates);
console.log([...map.values()]);Edit
To take arrays as input, create a function
const inspect = (...arrays) => {
const duplicates = [];
const map = new Map();
const fill = (array) => array.forEach(item => {
if (map.has(item.id)) {
duplicates.push(item);
} else {
map.set(item.id, item);
}
});
arrays.forEach(array => fill(array));
console.log(duplicates);
console.log([...map.values()]);
};
const array1 = [
{ id: 1, name: "Oliver" },
{ id: 2, name: "Liam" },
];
const array2 = [
{ id: 1, name: "Oliver" },
{ id: 3, name: "James" },
{ id: 4, name: "Lucas" },
];
inspect(array1, array2);You could take a Set from array2with all id and filter the other array.
const
array1 = [{ id: 1, name: "Oliver" }, { id: 2, name: "Liam" }],
array2 = [{ id: 1, name: "Oliver" }, { id: 3, name: "James" }, { id: 4, name: "Lucas" }],
set2 = new Set(array2.map(({ id }) => id)),
duplicateContacts = array1.filter(({ id }) => set2.has(id));
allContacts = [...array1, ...array2].filter(
(s => ({ id }) => !s.has(id) && s.add(id))
(new Set)
),
console.log("allContacts:", allContacts);
console.log("duplicateContacts:", duplicateContacts);.as-console-wrapper { max-height: 100% !important; top: 0; }with three methods :
filter to get an array of duplicate element
map to recover only an array of one column
some to describe how object in array should be compared
const duplicates = array1.filter(value => array2.some(oneElement => oneElement.id === value.id));
const duplicatesId = array1.filter(value => array2.some(oneElement => oneElement.id === value.id)).map(oneElement => oneElement.id);
const mergedArray = [
...array1,
...array2.filter(value => !duplicatesId.some(oneDuplicate => oneDuplicate === value.id))
];
const array1 = [
{ id: 1, name: "Oliver" },
{ id: 2, name: "Liam" },
];
const array2 = [
{ id: 1, name: "Oliver" },
{ id: 3, name: "James" },
{ id: 4, name: "Lucas" },
];
const duplicates = array1.filter(value => array2.some(oneElement => oneElement.id === value.id));
const duplicatesId = array1.filter(value => array2.some(oneElement => oneElement.id === value.id)).map(oneElement => oneElement.id);
const mergedArray = [
...array1,
...array2.filter(value => !duplicatesId.some(oneDuplicate => oneDuplicate === value.id))
];
console.log(duplicates);
console.log(duplicatesId);
console.log(mergedArray);