Example 1: how to remove duplicate array object in javascript
let person = [{name: "john"}, {name: "jane"}, {name: "imelda"}, {name: "john"}];
function removeDuplicates(data, key) {
return [
...new Map(data.map(item => [key(item), item])).values()
]
};
console.log(removeDuplicates(person, item => item.name));
Example 2: how to remove duplicate array object in javascript
var arrayWithDuplicates = [
{"type":"LICENSE", "licenseNum": "12345", state:"NV"},
{"type":"LICENSE", "licenseNum": "A7846", state:"CA"},
{"type":"LICENSE", "licenseNum": "12345", state:"OR"},
{"type":"LICENSE", "licenseNum": "10849", state:"CA"},
{"type":"LICENSE", "licenseNum": "B7037", state:"WA"},
{"type":"LICENSE", "licenseNum": "12345", state:"NM"}
];
function removeDuplicates(originalArray, prop) {
var newArray = [];
var lookupObject = {};
for(var i in originalArray) {
lookupObject[originalArray[i][prop]] = originalArray[i];
}
for(i in lookupObject) {
newArray.push(lookupObject[i]);
}
return newArray;
}
var uniqueArray = removeDuplicates(arrayWithDuplicates, "licenseNum");
console.log("uniqueArray is: " + JSON.stringify(uniqueArray));
Example 3: remove duplicates from array of objects javascript
arr.filter((v,i,a)=>a.findIndex(t=>(t.place === v.place && t.name===v.name))===i)
Example 4: combine 2 "arrays with objects" and remove object duplicates javascript
const joinWithoutDupes = (A, B) => {
const a = new Set(A.map(x => x.item))
const b = new Set(B.map(x => x.item))
return [...A.filter(x => !b.has(x.item)), ...B.filter(x => !a.has(x.item))]
}
const output = joinWithoutDupes([{item:"apple",description: "lorem"},{item:"peach",description: "impsum"}], [{item:"apple", description: "dolor"},{item:"grape", description: "enum"}])
console.log(output)