Question 286834 in Javascript Question posted in
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Javascript – From one array create another array

For example I have this JSON data:

const data = [
{
  title: 'Nike Dunk Low Panda',
  sku: 'DD1391-100',
  size: '9 US',
},
{
  title: 'Nike Dunk Low Panda',
  sku: 'DD1391-100',
  size: '10 US',
},
{
  title: 'Nike Dunk Low Panda',
  sku: 'DD1391-100',
  size: '11 US',
},
]

How to create another array like:

const data = [
{
  title: 'Nike Dunk Low Panda',
  sku: 'DD1391-100',
  size: '9 US, 10 US, 11 US'
}

]

I’m new in JS, trying to learn it )

Tags:

3

Answers


  1. 0 
    const data = [{
    title: 'Nike Dunk Low Panda',
    sku: 'DD1391-100',
    size: '9 US',
  },
  {
    title: 'Nike Dunk Low Panda',
    sku: 'DD1391-100',
    size: '10 US',
  },
  {
    title: 'Nike Dunk Low Panda',
    sku: 'DD1391-100',
    size: '11 US',
  },
]

sizeList = []

for (x of data) {
  sizeList.push(x['size'])
}

console.log({
  title: 'Nike Dunk Low Panda',
  sku: 'DD1391-100',
  size: sizeList
})
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  2. 0

    One way to do it is to create a new array by aggregating the sizes for each unique combination of title and sku

    • Create a map to store aggregated data
    • Iterate over the original data
    • Generate a unique key based on title and sku
    • Check if the key exists in the map
    • Append the size to the existing entry
    • Create a new entry in the map
    • Convert the map values to an array
    const originalData = [
  {
    title: 'Nike Dunk Low Panda',
    sku: 'DD1391-100',
    size: '9 US',
  },
  {
    title: 'Nike Dunk Low Panda',
    sku: 'DD1391-100',
    size: '10 US',
  },
  {
    title: 'Nike Dunk Low Panda',
    sku: 'DD1391-100',
    size: '11 US',
  },
];

const aggregatedMap = new Map();

originalData.forEach((item) => {
  const key = `${item.title}-${item.sku}`;

  if (aggregatedMap.has(key)) {
    aggregatedMap.get(key).size += `, ${item.size}`;
  } else {
    aggregatedMap.set(key, { title: item.title, sku: item.sku, size: item.size });
  }
});

//result
const newData = Array.from(aggregatedMap.values());

console.log(newData);
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  3. 0

    You could group by two keys and map the result by getting the wanted property from the group.

    const
    data = [{ title: 'Nike Dunk Low Panda', sku: 'DD1391-100', size: '9 US' }, { title: 'Nike Dunk Low Panda', sku: 'DD1391-100', size: '10 US' }, { title: 'Nike Dunk Low Panda', sku: 'DD1391-100', size: '11 US' }],
    keys = ['title', 'sku'],
    result = Object
        .values(Object.groupBy(data, o => keys.map(k => o[k]).join('|')))
        .map(a => ({ ...a[0], size: a.map(({ size }) => size).join(', ') }));

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