mapping an array of strings to an array of numbers based on key value pairs of another object

Question

I am trying to map an array of strings

arrString = [
      ["A", "B"],
      ["C", "D"],
      ["E", "F"],
      ["D", "A"],
      ["F", "C"],
      ["G", "E"]
    ] 

based on an object of key values:

map =  {
  '0': 'A',
  '1': 'B',
  '2': 'C',
  '3': 'D',
  '4': 'E',
  '5': 'F',
  '6': 'G'
}

into an array of numbers

arrNum = [
      ["0", "1"],
      ["2", "3"],
      ["4", "5"],
      ["3", "0"],
      ["5", "2"],
      ["6", "4"]
    ] 

This is what I have done:

    const map = {}
    const arrNum = Array.from(new Array(arrString.length), () => new Array(arrString[0].length).fill([]));
    for(let i = 0; i < arr2.length; i++){
        map[i] = arr2[i]
    }
    for(let ele in arrString){
    // I can't figure out how to if the obbject value is equal to ele push it's key to arrNum
        if (Object.values(map).includes(ele)) 
    }

As you can see I am trying to loop through arrString and then if any element equals a value in map I want to add its key to arrNum.

So anyone knows how to do it so I can end up with arrNum ?

Answer 1

 const arrString = [ ["A", "B"], ["C", "D"], ["E", "F"], ["D", "A"], ["F", "C"], ["G", "E"] ] map = { '0': 'A', '1': 'B', '2': 'C', '3': 'D', '4': 'E', '5': 'F', '6': 'G' } const arrNum = arrString.map(as => as.map(a => { for(const k in map){ if (map[k] === a) return k; } })); console.log(arrNum);

Answer 2

You can use:

 const arrString = [ ["A", "B"], ["C", "D"], ["E", "F"], ["D", "A"], ["F", "C"], ["G", "E"] ]; map = { '0': 'A', '1': 'B', '2': 'C', '3': 'D', '4': 'E', '5': 'F', '6': 'G' }; const keys = Object.keys(map); const arrNum = arrString.map(item => item.map(value => keys.find(key => map[key] === value))); console.log(arrNum);

Answer 3

First invert the map, then use it to match the letters.

 const arrString = [ ["A", "B"], ["C", "D"], ["E", "F"], ["D", "A"], ["F", "C"], ["G", "E"] ] const map = { '0': 'A', '1': 'B', '2': 'C', '3': 'D', '4': 'E', '5': 'F', '6': 'G' } const invertedMap = Object.fromEntries(Object.entries(map).map(([a,b])=>[b,a])) console.log('Inverted Map:',invertedMap) const output = arrString.map(inner => inner.map(char => invertedMap[char])) console.log('Result:',output)