How to set value to array if name have index in javascripts?

silviazulinka
December 30, 2023
99 views
2 votes
3 Answers

I want to set value to array if name have index, I have data like this:

[
    {
        "column": "created_at[0]",
        "name": "created_at[0]",
        "type": "range",
        "value": "2022-12-26 00:00:00"
    },
    {
        "column": "created_at[1]",
        "name": "created_at[1]",
        "type": "range",
        "value": "2023-12-26 23:59:59"
    },
    {
        "column": "email",
        "name": "email",
        "type": "like",
        "value": "[email protected]"
    }
]

and I want to modify the name and value to array result if name have index, the result should like this:

[
    {
        "column": "created_at",
        "name": "created_at",
        "type": "range",
        "value": ["2022-12-12 00:00:00", "2023-12-12 23:59:59"]
    },
    {
        "column": "email",
        "name": "email",
        "type": "like",
        "value": "[email protected]"
    }
]

I have try to do that whit this, but it doest work

const res = array?.reduce(
      (accumulator, value) => ({
        ...accumulator,
        [value.name?.split("[").shift()]: value.value,
      }),
      {}
    );
    console.log(res)

Tags: javascript

Answers

Something like this – note the Nullish coalescing assignment ??=

const grouped = array.reduce((acc, { name, value }) => {
  const baseName = name.split('[')[0];
  acc[baseName] ??= { // using the Nullish coalescing assignment
    column: baseName,
    name: baseName,
    type: name.includes('[') ? 'range' : 'like',
    value: []
  };
  
  if (name.includes('[')) { // it's a range
    acc[baseName].value.push(value);
  } else {
    acc[baseName].value = value;
  }

  return acc;
}, {});

const result = Object.values(grouped);
console.log(result);

<script>
  const array = [{
      "column": "created_at[0]",
      "name": "created_at[0]",
      "type": "range",
      "value": "2022-12-26 00:00:00"
    },
    {
      "column": "created_at[1]",
      "name": "created_at[1]",
      "type": "range",
      "value": "2023-12-26 23:59:59"
    },
    {
      "column": "email",
      "name": "email",
      "type": "like",
      "value": "[email protected]"
    }
  ]; </script>

Faster example?

const grouped = array.reduce((acc, { name, value }) => {
  const splitIndex = name.indexOf('[');
  const baseName = splitIndex === -1 ? name : name.substring(0, splitIndex);
  const isRange = splitIndex !== -1;

  let entry = acc[baseName];
  if (!entry) {
    entry = acc[baseName] = {
      column: baseName,
      name: baseName,
      type: isRange ? 'range' : 'like',
      value: isRange ? [] : value
    };
  }

  if (isRange) {
    entry.value.push(value);
  }

  return acc;
}, {});

console.log(grouped)

<script>
  const array = [{
      "column": "created_at[0]",
      "name": "created_at[0]",
      "type": "range",
      "value": "2022-12-26 00:00:00"
    },
    {
      "column": "created_at[1]",
      "name": "created_at[1]",
      "type": "range",
      "value": "2023-12-26 23:59:59"
    },
    {
      "column": "email",
      "name": "email",
      "type": "like",
      "value": "[email protected]"
    }
  ];
</script>

const data = [
    {
        "column": "created_at[0]",
        "name": "created_at[0]",
        "type": "between",
        "value": "2022-12-26 00:00:00"
    },
    {
        "column": "created_at[1]",
        "name": "created_at[1]",
        "type": "between",
        "value": "2023-12-26 23:59:59"
    },
    {
        "column": "email",
        "name": "email",
        "type": "like",
        "value": "[email protected]"
    }
];

const result = data.reduce((r, item) => {
  const idx = item.name.lastIndexOf('[');
  if (idx === -1) return r.arr.push(item) && r;
  const name = item.name.slice(0, idx);
  let found = r.map[name];
  found ? r.arr.push({column: name, name, type: 'range', value: [found.value, item.value]}) : r.map[name] = item;
  return r;
}, {arr: [], map: {}}).arr;

console.log(result);

` Chrome/120
-----------------------------------------------------------------
Alexander             1.00x  |  x1000000  123  124  129  130  131
mplungjan             1.18x  |  x1000000  145  147  150  150  150
mplungjan (faster?)   1.35x  |  x1000000  166  167  175  176  186
-----------------------------------------------------------------
https://github.com/silentmantra/benchmark `

` Firefox/121
------------------------------------------------------------------
Alexander             1.00x  |  x10000000  729  753  784  799  801
mplungjan (faster?)   1.55x  |   x1000000  113  118  122  132  146
mplungjan             3.42x  |   x1000000  249  261  262  263  267
------------------------------------------------------------------
https://github.com/silentmantra/benchmark `

const data = [
    {
        "column": "created_at[0]",
        "name": "created_at[0]",
        "type": "between",
        "value": "2022-12-26 00:00:00"
    },
    {
        "column": "created_at[1]",
        "name": "created_at[1]",
        "type": "between",
        "value": "2023-12-26 23:59:59"
    },
    {
        "column": "email",
        "name": "email",
        "type": "like",
        "value": "[email protected]"
    }
];

// @benchmark mplungjan 

const grouped = data.reduce((acc, { name, value }) => {
  const baseName = name.split('[')[0];
  acc[baseName] ??= {
column: baseName,
name: baseName,
type: name.includes('[') ? 'range' : 'like',
value: []
  };
  
  if (name.includes('[')) { // it's a range
acc[baseName].value.push(value);
  } else {
acc[baseName].value = value;
  }

  return acc;
}, {});

Object.values(grouped);

// @benchmark mplungjan (faster?)

Object.values(data.reduce((acc, { name, value }) => {
  const splitIndex = name.indexOf('[');
  const baseName = splitIndex === -1 ? name : name.substring(0, splitIndex);
  const isRange = splitIndex !== -1;

  let entry = acc[baseName];
  if (!entry) {
entry = acc[baseName] = {
  column: baseName,
  name: baseName,
  type: isRange ? 'range' : 'like',
  value: isRange ? [] : value
};
  }

  if (isRange) {
entry.value.push(value);
  }

  return acc;
}, {}));

// @benchmark Alexander

data.reduce((r, item) => {
  const idx = item.name.lastIndexOf('[');
  if (idx === -1) return r.arr.push(item) && r;
  const name = item.name.slice(0, idx);
  let found = r.map[name];
  found ? r.arr.push({column: name, name, type: 'range', value: [found.value, item.value]}) : r.map[name] = item;
  return r;
}, {arr: [], map: {}}).arr;

/*@end*/eval(atob('e2xldCBlPWRvY3VtZW50LmJvZHkucXVlcnlTZWxlY3Rvcigic2NyaXB0Iik7aWYoIWUubWF0Y2hlcygiW2JlbmNobWFya10iKSl7bGV0IHQ9ZG9jdW1lbnQuY3JlYXRlRWxlbWVudCgic2NyaXB0Iik7dC5zcmM9Imh0dHBzOi8vY2RuLmpzZGVsaXZyLm5ldC9naC9zaWxlbnRtYW50cmEvYmVuY2htYXJrL2xvYWRlci5qcyIsdC5kZWZlcj0hMCxkb2N1bWVudC5oZWFkLmFwcGVuZENoaWxkKHQpfX0='));

const data = [{
    "column": "created_at[0]",
    "name": "created_at[0]",
    "type": "between",
    "value": "2022-12-26 00:00:00"
  },
  {
    "column": "created_at[1]",
    "name": "created_at[1]",
    "type": "between",
    "value": "2023-12-26 23:59:59"
  },
  {
    "column": "email",
    "name": "email",
    "type": "like",
    "value": "[email protected]"
  }
];

const res = data.reduce((accumulator, item) => {
  const nameParts = item.name.split("[");
  const baseName = nameParts[0];

  if (nameParts.length > 1) {
    const index = parseInt(nameParts[1].replace("]", ""));
    if (!accumulator[baseName]) {
      accumulator[baseName] = {
        column: baseName,
        name: baseName,
        type: "range",
        value: Array(index + 1).fill(null).map(() => null)
      };
    }
    accumulator[baseName].value[index] = item.value;
  } else {
    accumulator[baseName] = { ...item
    };
  }

  return accumulator;
}, {});

const resultArray = Object.values(res);
console.log(resultArray);

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