Total the values of several items within the array

Question

Total the values of several items within the array

Here is the data I currently have:

const arrayA = [{name:'a', amount: 10, serviceId: '23a', test:'SUCCESS'},
                {name:'a', amount: 9, test:'FAIL'}, 
                {name:'b', amount: 15, serviceId: '23b', test:'SUCCESS'}]

(note: there are objects without a 'serviceId')

This is what I want to achieve:

 [{name:'a', amount: 19, test:'FAIL'},
  {name:'b', amount: 15, test:'SUCCESS'}]

I need to sum the amount field based on the name grouping.
The 'test' field should be set as FAIL if there is any object with the value of FAIL (grouped by name).
I am not concerned about the value of serviceId and do not wish to include it in the new object.

After searching, I attempted the following code:

const result = Object.values(arrayA.reduce((r, o) => (r[o.name]
  ? (r[o.name].amount += o.amount)
  : (r[o.name] = {...o}), r), {}));

However, I'm unsure how to assign the test field. Any assistance would be greatly appreciated!

javascript typescript reduce

Answer 1

Answer №1

To proceed, you must verify the value of test and make the necessary updates.

const
    array = [{ name: 'a', amount: 10, serviceId: '23a', test: 'SUCCESS' }, { name: 'a', amount: 9, test: 'FAIL' }, { name: 'b', amount: 15, serviceId: '23b', test: 'SUCCESS' }],
    result = Object.values(array.reduce((r, { name, amount, test }) => {
        if (!r[name]) r[name] = { name, amount: 0, test };
        r[name].amount += amount;
        if (test === 'FAIL') r[name].test = 'FAIL';
        return r;
    }, {}));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

To proceed, you must verify the value of test and make the necessary updates.

const
    array = [{ name: 'a', amount: 10, serviceId: '23a', test: 'SUCCESS' }, { name: 'a', amount: 9, test: 'FAIL' }, { name: 'b', amount: 15, serviceId: '23b', test: 'SUCCESS' }],
    result = Object.values(array.reduce((r, { name, amount, test }) => {
        if (!r[name]) r[name] = { name, amount: 0, test };
        r[name].amount += amount;
        if (test === 'FAIL') r[name].test = 'FAIL';
        return r;
    }, {}));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 3

Answer №2

This is a simple test to check if the .test property has failed

const arrayA = [{ name: 'a', amount: 10, serviceId: '23a', test: 'SUCCESS' }, { name: 'a', amount: 9, test: 'FAIL' }, { name: 'b', amount: 15, serviceId: '23b', test: 'SUCCESS' }],
  result = Object.values(
    arrayA.reduce((r, o) => {
      r[o.name] ? (r[o.name].amount += o.amount) : (r[o.name] = { ...o })
      r[o.name].test = r[o.name].test === "FAIL" ? "FAIL" : o.test;
      return r;
    }, {})
  );

console.log(result);

Answer 4

This is a simple test to check if the .test property has failed

const arrayA = [{ name: 'a', amount: 10, serviceId: '23a', test: 'SUCCESS' }, { name: 'a', amount: 9, test: 'FAIL' }, { name: 'b', amount: 15, serviceId: '23b', test: 'SUCCESS' }],
  result = Object.values(
    arrayA.reduce((r, o) => {
      r[o.name] ? (r[o.name].amount += o.amount) : (r[o.name] = { ...o })
      r[o.name].test = r[o.name].test === "FAIL" ? "FAIL" : o.test;
      return r;
    }, {})
  );

console.log(result);

Answer 5

Answer №3

Store the total amounts and final test results in an object, then convert them into an array.

const dataPoints = [
  { label: "alpha", value: 10, id: "30a", status: "PASS" },
  { label: "beta", value: 9, status: "FAIL" },
  { label: "gamma", value: 15, id: "30c", status: "PASS" },
];

const summary = {};

dataPoints.forEach((entry) => {
  if (!summary[entry.label]) {
    summary[entry.label] = { label: entry.label, value: 0, status: "PASS" };
  }

  summary[entry.label].value += entry.value;

  if (entry.status === "FAIL") {
    summary[entry.label].status = "FAIL";
  }
});

const finalResult = Object.values(summary);

console.log(finalResult);

Answer 6

Store the total amounts and final test results in an object, then convert them into an array.

const dataPoints = [
  { label: "alpha", value: 10, id: "30a", status: "PASS" },
  { label: "beta", value: 9, status: "FAIL" },
  { label: "gamma", value: 15, id: "30c", status: "PASS" },
];

const summary = {};

dataPoints.forEach((entry) => {
  if (!summary[entry.label]) {
    summary[entry.label] = { label: entry.label, value: 0, status: "PASS" };
  }

  summary[entry.label].value += entry.value;

  if (entry.status === "FAIL") {
    summary[entry.label].status = "FAIL";
  }
});

const finalResult = Object.values(summary);

console.log(finalResult);

Answer 7

Answer №4

That's a great example of data processing in JavaScript, showcasing how functions like map and reduce can simplify the process without relying on traditional loops.

It's recommended to break down the processing into steps as outlined in your description. Here's an illustration:

const arrayA = [
    {name:'a', amount: 10, serviceId: '23a', test:'SUCCESS'},
    {name:'a', amount: 9, test:'FAIL'},
    {name:'b', amount: 15, serviceId: '23b', test:'SUCCESS'}
]

// Group items by name
const byName = arrayA.reduce((ob, item) => {
    if(!(item.name in ob))
        ob[item.name] = []
    ob[item.name].push({amount: item.amount, test: item.test})
    return ob
}, {})

// Calculate total amount in each group and check for any FAILs
const sumByName = Object.keys(byName).map(name => {
    const amount = byName[name].reduce((sum, item) => sum + item.amount , 0)
    const test = byName[name].map(item => item.test)
        .includes('FAIL') ? 'FAIL': 'SUCCESS'
    return ({name, amount, test})
})

console.log(sumByName)

Lastly, I recommend checking out these videos on map and reduce (and other related content from that channel):

Reduce
Map

Answer 8

That's a great example of data processing in JavaScript, showcasing how functions like map and reduce can simplify the process without relying on traditional loops.

It's recommended to break down the processing into steps as outlined in your description. Here's an illustration:

const arrayA = [
    {name:'a', amount: 10, serviceId: '23a', test:'SUCCESS'},
    {name:'a', amount: 9, test:'FAIL'},
    {name:'b', amount: 15, serviceId: '23b', test:'SUCCESS'}
]

// Group items by name
const byName = arrayA.reduce((ob, item) => {
    if(!(item.name in ob))
        ob[item.name] = []
    ob[item.name].push({amount: item.amount, test: item.test})
    return ob
}, {})

// Calculate total amount in each group and check for any FAILs
const sumByName = Object.keys(byName).map(name => {
    const amount = byName[name].reduce((sum, item) => sum + item.amount , 0)
    const test = byName[name].map(item => item.test)
        .includes('FAIL') ? 'FAIL': 'SUCCESS'
    return ({name, amount, test})
})

console.log(sumByName)

Lastly, I recommend checking out these videos on map and reduce (and other related content from that channel):

Reduce
Map

Answer 9

Answer №5

One way to achieve this is by using the Array.reduce method:

const arrayA=[{name:"a",amount:10,serviceId:"23a",test:"SUCCESS"},{name:"a",amount:9,test:"FAIL"},{name:"b",amount:15,serviceId:"23b",test:"SUCCESS"}];

let result  = arrayA.reduce((aac,{name,amount,test}) => {
    let idx = aac.findIndex(n => n.name === name)
    if( idx != -1){
        aac[idx].amount += amount;
        if(test === "FAIL")
            aac[idx].test = "FAIL"        
        return aac
    }
    aac.push({name,amount,test})
    return aac
},[])

console.log(result);
console.log(arrayA)

Answer 10

One way to achieve this is by using the Array.reduce method:

const arrayA=[{name:"a",amount:10,serviceId:"23a",test:"SUCCESS"},{name:"a",amount:9,test:"FAIL"},{name:"b",amount:15,serviceId:"23b",test:"SUCCESS"}];

let result  = arrayA.reduce((aac,{name,amount,test}) => {
    let idx = aac.findIndex(n => n.name === name)
    if( idx != -1){
        aac[idx].amount += amount;
        if(test === "FAIL")
            aac[idx].test = "FAIL"        
        return aac
    }
    aac.push({name,amount,test})
    return aac
},[])

console.log(result);
console.log(arrayA)

Total the values of several items within the array

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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