I would like to do something which seems very easy but I haven't found the solution yet (I didn't find anything on the forum of course).

I want to separate one element of an array, in two.

For instance: I have an array

let array = [
  [ '201026 21330', '12385', '852589', '951478' ],
  [ '201026 21320', '12385', '369874' ]
]

I want to split the first element like that (notice the first elements, here separated):

let result = 
[
 [ '201026','21330', '12385', '852589', '951478' ],
 [ '201026','21320', '12385', '369874' ]
]

Does anybody have any clue?

Thanks in advance

I would like to do something which seems very easy but I haven't found the solution yet (I didn't find anything on the forum of course).

I want to separate one element of an array, in two.

For instance: I have an array

let array = [
  [ '201026 21330', '12385', '852589', '951478' ],
  [ '201026 21320', '12385', '369874' ]
]

I want to split the first element like that (notice the first elements, here separated):

let result = 
[
 [ '201026','21330', '12385', '852589', '951478' ],
 [ '201026','21320', '12385', '369874' ]
]

Does anybody have any clue?

Thanks in advance

• javascript
• node.js

4 Answers 4

Use Array#map, String#split and Array#flat

const arr = [
  [ '201026 21330', '12385', '852589', '951478' ],
  [ '201026 21320', '12385', '369874' ]
]

const res = arr.map(row => row.map(item => item.split(' ')).flat());

console.log(res)

You could separate the first item, split it and get all elements in a new array.

let array = [['201026 21330', '12385', '852589', '951478'], ['201026 21320', '12385', '369874']],
    result = array.map(([s, ...rest]) => [...s.split(' '), ...rest]);

console.log(result);

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You can do this pretty easily through a bination of methods, namely the array method flatMap and the string method split.

let array = [
  [ '201026 21330', '12385', '852589', '951478' ],
  [ '201026 21320', '12385', '369874' ]
]

let result = array.map(
  sub => sub.flatMap(
    element => element.split(' ')
  )
);

Looping through each of the subarrays, splitting each element by spaces and then flattening the subarray. This will take care of any double elements in the array, not just the first.

What you want to do is loop through each sub-array of the two-dimensional array. Then, you can process each sub-array individually, which makes the problem a little easier. For this, you can use Array.prototype.map which allows you to apply a function to each element of the array:

[0,1,2].map(x => x + 1) gives [1,2,3]. Equivalently, without using a lambda (fat arrow) function, you could write [0,1,2].map(function (x) { return x + 1; }).

Then you split the first element by a space, and return the two halves along with the rest of the array. You need to add two lists row[0].split(' ') and row.slice(1) to do this.

function splitFirst (array) {
  return array.map(row =>
    [...row[0].split(' '), ...row.slice(1)]
  );
}