I've an array of objects:
[
{ name: "John", age: "34" },
{ name: "Ace", age: "14" },
{ name: "John", age: "45" },
{ name: "Harry", age: "11" },
]
I want to compare the objects within an array by name. If the duplicate name exists, I should compare the age and only keep the higher age object.
The expected output should be:
[
{ name: "Ace", age: "14" },
{ name: "John", age: "45" },
{ name: "Harry", age: "11" },
]
I am new to javascript/typescript and couldn't find any optimal solution for this problem. I hope, I was able to explain my problem clearly.
Thanks.
Maybe something like that
const obj = [{ name: "John", age: "34" }, { name: "Ace", age: "14" }, { name: "John", age: "45" }, { name: "Harry", age: "11" }];
const objCopy = JSON.parse(JSON.stringify(obj))
const res = objCopy.reduce((acc, obj) => {
const personExist = acc.find(({ name }) => name === obj.name);
if (personExist) {
if (parseInt(obj.age, 10) > parseInt(personExist.age, 10)) {
personExist.age = obj.age;
}
} else {
acc.push(obj);
}
return acc;
}, []);
console.log({ res });.as-console-wrapper { min-height: 100%!important; top: 0; }The next provided approach uses reduce and creates in a first step just an index/map of items of highest age which are each unique by name. Thus one could use the temporary state of the programmatically built result as lookup for already existing named items.
Within a second step one would retrieve the array of unique named items of highest age by passing such an index to Object.values.
function collectHighestAgeItemOfSameName(result, item) {
const { name, age } = item;
if (
!(name in result) ||
Number(result[name].age) < Number(age)
) {
result[name] = item;
}
return result;
}
const sampleData = [{
name: "John",
age: "34"
}, {
name: "Ace",
age: "14"
}, {
name: "Harry",
age: "9"
}, {
name: "John",
age: "45"
}, {
name: "Harry",
age: "11"
}, {
name: "Ace",
age: "13"
}];
console.log(
'reduced index of unique person items of highest age ...',
sampleData
.reduce(collectHighestAgeItemOfSameName, {})
)
console.log(
'array of unique person items of highest age ...',
Object
.values(
sampleData
.reduce(collectHighestAgeItemOfSameName, {})
)
).as-console-wrapper { min-height: 100%!important; top: 0; }try this
var objArr=...your json object;
var maxValueGroup = "name";
var maxValueName = "age";
console.log(JSON.stringify(newArr(objArr,maxValueGroup, maxValueName)));
newArr
var newArr = function (objArr,maxValueGroup, maxValueName) {
var arr = groupBy(objArr, maxValueGroup);
var newArr = [];
$.each(arr, function (key) {
var maxVal = 0;
var maxValItem;
arr[key].forEach((element) => {
if (element[maxValueName] > maxVal) {
maxVal = element[maxValueName];
maxValItem = element;
}
});
newArr.push(maxValItem);
});
return newArr;
};
groupby
var groupBy = function (xs, key) {
return xs.reduce(function (rv, x) {
(rv[x[key]] = rv[x[key]] || []).push(x);
return rv;
}, {});
};