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Aggregate records in JavaScript
Let’s say, we have an array of objects that contains information about some random transactions carried out by some people −
const transactions = [{
name: 'Rakesh',
amount: 1500
}, {
name: 'Rajesh',
amount: 1200
}, {
name: 'Ramesh',
amount: 1750
}, {
name: 'Rakesh',
amount: 2100
}, {
name: 'Mukesh',
amount: 1100
}, {
name: 'Rajesh',
amount: 1950
}, {
name: 'Mukesh',
amount: 1235
}, {
name: 'Ramesh',
amount: 2000
}];We are required to write a function that takes in this array and aggregates and returns the transaction amount of unique people in distinct objects.
Therefore, let’s write the code for this function −
Example
const transactions = [{
name: 'Rakesh',
amount: 1500
}, {
name: 'Rajesh',
amount: 1200
}, {
name: 'Ramesh',
amount: 1750
}, {
name: 'Rakesh',
amount: 2100
}, {
name: 'Mukesh',
amount: 1100
}, {
name: 'Rajesh',
amount: 1950
}, {
name: 'Mukesh',
amount: 1235
}, {
name: 'Ramesh',
amount: 2000
}];
const aggregateArray = arr => {
return arr.reduce((acc, val) => {
const index = acc.findIndex(obj => obj.name === val.name);
if(index !== -1){
acc[index].amount += val.amount;
}else{
acc.push({
name: val.name,
amount: val.amount
});
};
return acc;
}, []);
};
console.log(aggregateArray(transactions));Output
The output in the console will be −
[
{ name: 'Rakesh', amount: 3600 },
{ name: 'Rajesh', amount: 3150 },
{ name: 'Ramesh', amount: 3750 },
{ name: 'Mukesh', amount: 2335 }
]
Updated on: 26-Aug-2020
2K+ Views
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