Example 1: remove duplicate objects from array javascript
const addresses = [...];
const uniqueAddresses = Array.from(new Set(addresses.map(a => a.id)))
.map(id => {
return addresses.find(a => a.id === id)
})
Example 2: filter duplicate value in array of object typescript
var arrOfObj = [
{
id:1 ,name:'abc',age:27
},
{
id:2 ,name:'pqr',age:27
},
{
id:1 ,name:'abc',age:27
},
]
var setObj = new Set();
var result = arrOfObj.reduce((acc,item)=>{
if(!setObj.has(item.age)){
setObj.add(item.age)
acc.push(item)
}
return acc;
},[]);
console.log(result);
Example 3: Removing duplicates in an Array of Objects
const seen = new Set();
const arr = [
{ id: 1, name: "test1" },
{ id: 2, name: "test2" },
{ id: 2, name: "test3" },
{ id: 3, name: "test4" },
{ id: 4, name: "test5" },
{ id: 5, name: "test6" },
{ id: 5, name: "test7" },
{ id: 6, name: "test8" }
];
const filteredArr = arr.filter(el => {
const duplicate = seen.has(el.id);
seen.add(el.id);
return !duplicate;
});
Example 4: 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));