How can I turn a string of numbers into a Matrix?

Question

I’m doing an exercise where I should extract rows and columns from a string, creating an array.

Input let str = '1 2 3\n4 5 6\n7 8 9', I wrote a code that returns: [ '4 5 6' ], but I’d like him to return something like: [4, 5, 6] (not between quotes). How can I do this?

let str = '1 2 3\n4 5 6\n7 8 9'
let arr = str.split('\n');
    let rowResult = [];
    let rowFinalResult = [];

    for(let i = 0; i < arr.length; i++){
        rowResult = arr[i];
        rowFinalResult.push([rowResult]);
    }
    console.log(rowFinalResult[1]);

Answer 1

With the str.split('\n'), you are splitting the original string a array with three other strings, separated by '\n'.

However, for each of these three new strings, you must separate them again so as to "individualize" each numeric string (by separating by space ' '). Behold:

let str = '1 2 3\n4 5 6\n7 8 9';

let arr = str.split('\n');
for (let i = 0; i < arr.length; i++) {
  arr[i] = arr[i].split(' ');
}

console.log(arr);

To turn each string into a number, we can use the map. Note in the above code that the expression arr[i].split(' ') returns a array. Thus, using the Array.prototype.map, we can map each element to a number (by converting them using the parseInt).

let str = '1 2 3\n4 5 6\n7 8 9';

let arr = str.split('\n');
for (let i = 0; i < arr.length; i++) {
  arr[i] = arr[i]
    .split(' ')
    .map((str) => parseInt(str, 10));
}

console.log(arr);

Answer 2

In this case, what you would need to do is the following, when you get the "rowResult", you get a string where the numbers are separated by spaces. If you replace the space by comma, you will arrive at the desired result, this can be done using the "replaceAll" method. Your code would look like this:

let str = '1 2 3\n4 5 6\n7 8 9'
let arr = str.split('\n');
let rowResult = [];
let rowFinalResult = [];

for(let i = 0; i < arr.length; i++){
    rowResult = arr[i];
    rowFinalResult.push(rowResult.replaceAll(' ',','));
}
console.log(rowFinalResult[1]);