CODEWITHSUNDEEP
javascriptarraystypescript
Stéphane GRILLON
Stéphane GRILLON

Reputation: 11862

How to concat sub array in typescript or javascript?

How to concat sub array in typescript or javascript? In may case I want concat all values with same name.

My array is

[
  {
    name: "AAA"
    values: [[1573054321, 0], [1573054560, 0]]
  }, {
    name: "BBB"
    values: [[1573054388, 0], [1573054596, 0]]
  }
], [
  {
    name: "AAA"
    values: [[1573054355, 0], [1573054542, 0]]
  }, {
    name: "BBB"
    values: [[1573054325, 0], [1573054545, 0]]
  }
]

I want this in my output:

[
  {
    name: "AAA"
    values: [[1573054321, 0], [1573054560, 0], [1573054355, 0], [1573054542, 0]]
  }, {
    name: "BBB"
    values: [[1573054388, 0], [1573054596, 0], [1573054325, 0], [1573054545, 0]]
  }
]

My typescript exemple with a simple concat (allMetricSeries is my input):

let metricSeries: MetricSeries[] = [];
allMetricSeries.forEach(metrics => {
  metricSeries = metricSeries.concat(metrics);
});

Upvotes: 0

Views: 1122

Answers (4)

StepUp
StepUp

Reputation: 38114

Another way through reduce method and spread operator:

let data = [
    [
        {
            name: "AAA",
            values: [[1573054321, 0], [1573054560, 0]]
        }, {
            name: "BBB",
            values: [[1573054388, 0], [1573054596, 0]]
        }
    ],
    [
        {
            name: "AAA",
            values: [[1573054355, 0], [1573054542, 0]]
        }, {
            name: "BBB",
            values: [[1573054325, 0], [1573054545, 0]]
        }
    ]
];


const result = data.reduce((a, c) => {
    let innerResult = c.reduce((ia, ic) => {
        ia[ic.name] = ia[ic.name] || {name: ic.name, values:[]};
        ia[ic.name].values.push(ic.values);
        return ia;
    }, {});

    for (const key in innerResult) {
        a[key] = a[key] || {values: []};
        a[key].values.push(...innerResult[key].values);
    }
    return a;
}, {});    
console.log(result);

Upvotes: 0

Anis R.
Anis R.

Reputation: 6912

One way would be to first build a dictionary of the form name => values, and then building our target array from that dictionary (by generating an object of the form {name: values} from each entry in the dictionary)

//your initial array
var arr = [[
  {
    name: "AAA",
    values: [[1573054321, 0], [1573054560, 0]]
  }, {
    name: "BBB",
    values: [[1573054388, 0], [1573054596, 0]]
  }
], [
  {
    name: "AAA",
    values: [[1573054355, 0], [1573054542, 0]]
  }, {
    name: "BBB",
    values: [[1573054325, 0], [1573054545, 0]]
  }
]];

//temporary dictionary to help us build the new array
//of the form {'AAA' => [values], 'BBB' => [values]}
var dict = {};

for(var sub of arr) {
  for(var x of sub) {
    if(dict[x.name]) {
      dict[x.name] = dict[x.name].concat(x.values);
    }
    else {
      dict[x.name] = x.values;
    }
  }
}

//now building the new array from the dictionary:
var new_arr = [];
for (key in dict) {
  new_arr.push({name:key, values:dict[key]});
}

console.log(new_arr);

Upvotes: 1

Nicolas
Nicolas

Reputation: 8670

You can use a simple loop with a new array to accomplish this. 

let array = [
  [{
    name: "AAA",
    values: [[1573054321, 0], [1573054560, 0]]
  }, 
  {
    name: "BBB",
    values: [[1573054388, 0], [1573054596, 0]]
  }],
  [{
    name: "AAA",
    values: [[1573054355, 0], [1573054542, 0]]
  }, 
  {
    name: "BBB",
    values: [[1573054325, 0], [1573054545, 0]]
  }]
];

let output = {};
// we loop every array
array.forEach((subArray) => {
  // we loop every array of array
  subArray.forEach((data) => {
  // if the key does not exists, we create it.
   if(!output.hasOwnProperty(data.name)) {
      output[data.name] = {
        name: data.name,
        values: []
      };
    }
    // push the value.
     output[data.name].values = output[data.name].values.concat(data.values);
  })
});

// we returns only the values of our object.
console.log(Object.values(output));

Upvotes: 2

Rainer Plumer
Rainer Plumer

Reputation: 3753

One way of doing it.

resultObj = {};
[[
  {
    name: "AAA",
    values: [[1573054321, 0], [1573054560, 0]]
  }, {
    name: "BBB",
    values: [[1573054388, 0], [1573054596, 0]]
  }
], [
  {
    name: "AAA",
    values: [[1573054355, 0], [1573054542, 0]]
  }, {
    name: "BBB",
    values: [[1573054325, 0], [1573054545, 0]]
  }
]].forEach((subArray) => {
    subArray.forEach((arr) => {
        const name = arr.name;
        if (!resultObj[name]) {
            resultObj[name] = arr.values.slice();
        } else {
            resultObj[name].push(...arr.values);
        }
    });
});
finalResult = Object.keys(resultObj).map((key) => {
    return {name: key, values: resultObj[key]}
});

Upvotes: 0

Related Questions