CODEWITHSUNDEEP
javascriptarrays
Diza Moa
Diza Moa

Reputation: 61

Sorting nested Array inside Array using sort

I want to sort nested array (array inside an array) i.e My array looks like this

const input = [[3,9],[7,12],[3,8],[6,8],[9,10],[2,9],[0,9],[3,9],[0,6],[2,8]]

To do that I wrote this logic

const input = [[3,9],[7,12],[3,8],[6,8],[9,10],[2,9],[0,9],[3,9],[0,6],[2,8]]
    
    
     function sort (a,b) {
      if (a[0] < b[0]) return -1
      if (a[0] > b[0]) return 1
      if (a[0] === b[0]) {
        if (a.length > 1 && b.length > 1) {
          return sort(a.slice(0, 1), b.slice(0,1))
        }
        else return 0
      } 
    }

  console.log(input.sort((a,b) => {
    return sort(a,b)
  }))

but this is giving first element as [0,9] instead of [0, 6] and [2, 9] instead of [2,8] so on.

What I want is

So [0, 6] should be before [0,9]...

Upvotes: 0

Views: 364

Answers (1)

CertainPerformance
CertainPerformance

Reputation: 371233

All you need for the callback is a[0] - b[0] || a[1] - b[1]:

const input = [[3,9],[7,12],[3,8],[6,8],[9,10],[2,9],[0,9],[3,9],[0,6],[2,8]]
console.log(input.sort((a,b) => a[0] - b[0] || a[1] - b[1]))

If the array is of arbitrary length, then you do need a separate named function:

const sort = (a, b) => a[0] - b[0] || sort(a.slice(1), b.slice(1));

const input = [[3,9],[7,12],[3,8],[6,8],[9,10],[2,9],[0,9],[3,9],[0,6],[2,8]]
console.log(input.sort((a,b) => a[0] - b[0] || a[1] - b[1]))

Upvotes: 4

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