I desire to rearrange the items within several arrays of lists

Question

I desire to rearrange the items within several arrays of lists

I currently have an array set up like this

0: (5) ["2", "X", "8", "11", "15"] 
1: (5) ["1", "5", "X", "X", "14"]
2: (5) ["X", "4", "7", "10", "13"]
3: (5) ["X", "3", "6", "9", "12"]

My goal is to swap the position of the digit 1 with the position of digit 2 in order to get this desired outcome:

0: (5) ["1", "X", "8", "11", "15"]
1: (5) ["2", "5", "X", "X", "14"]
2: (5) ["X", "4", "7", "10", "13"]
3: (5) ["X", "3", "6", "9", "12"]

This array is returned all at once, so I need a way to rearrange the elements after it's returned.

Currently, I am working with JavaScript. Thank you in advance for any help or suggestions.

I attempted to use the following code snippet:

Array.prototype.move = function (from, to) {
this.splice(to, 0, this.splice(from, 1)[0]);
};

However, this code ends up moving entire rows together, rather than just swapping individual digits within the arrays.

javascript arrays angularjs

Answer 1

Answer №1

Identify the outer array index and inner array index for both elements, then perform a swap:

const input = [
 ["2", "X", "8", "11", "15"] ,
 ["1", "5", "X", "X", "14"],
 ["X", "4", "7", "10", "13"],
 ["X", "3", "6", "9", "12"]
];

const getLoc = char => {
  const arrIndex = input.findIndex(subarr => subarr.includes(char));
  const subArrIndex = input[arrIndex].indexOf(char);
  return [arrIndex, subArrIndex];
};
const move = (char1, char2) => {
  const [loc1, loc2] = [char1, char2].map(getLoc);
  
  [
    // switch position of first character:
    input[loc1[0]][loc1[1]],
    // and position of second character:
    input[loc2[0]][loc2[1]]
  ] = [
    // with position of second character:
    input[loc2[0]][loc2[1]],
    // and the first character:
    input[loc1[0]][loc1[1]]
  ];
};

move('2', '1');
console.log(input);

Answer 2

Identify the outer array index and inner array index for both elements, then perform a swap:

const input = [
 ["2", "X", "8", "11", "15"] ,
 ["1", "5", "X", "X", "14"],
 ["X", "4", "7", "10", "13"],
 ["X", "3", "6", "9", "12"]
];

const getLoc = char => {
  const arrIndex = input.findIndex(subarr => subarr.includes(char));
  const subArrIndex = input[arrIndex].indexOf(char);
  return [arrIndex, subArrIndex];
};
const move = (char1, char2) => {
  const [loc1, loc2] = [char1, char2].map(getLoc);
  
  [
    // switch position of first character:
    input[loc1[0]][loc1[1]],
    // and position of second character:
    input[loc2[0]][loc2[1]]
  ] = [
    // with position of second character:
    input[loc2[0]][loc2[1]],
    // and the first character:
    input[loc1[0]][loc1[1]]
  ];
};

move('2', '1');
console.log(input);

Answer 3

Answer №2

If you want to find the first index of "2" and "1" in their respective arrays using findIndex, you can do so and then replace them. Alternatively, if you only need to replace an element at a specific index, you can directly target that index within the array.

let data = [
  ["2", "X", "8", "11", "15"],
  ["1", "5", "X", "X", "14"]
];


let find2In1 = data[0].findIndex(item => item === "2");
let find1In2 = data[1].findIndex(item => item === "1");
data[0][find2In1] = "1";
data[1][find1In2] = "2";

console.log(data)

Answer 4

If you want to find the first index of "2" and "1" in their respective arrays using findIndex, you can do so and then replace them. Alternatively, if you only need to replace an element at a specific index, you can directly target that index within the array.

let data = [
  ["2", "X", "8", "11", "15"],
  ["1", "5", "X", "X", "14"]
];


let find2In1 = data[0].findIndex(item => item === "2");
let find1In2 = data[1].findIndex(item => item === "1");
data[0][find2In1] = "1";
data[1][find1In2] = "2";

console.log(data)

Answer 5

Answer №3

Based on the provided sample, it seems like you should switch between 1 and 2.

Example

0: (5) ["2", "X", "8", "11", "15"] 
1: (5) ["1", "5", "X", "X", "14"]
2: (5) ["X", "4", "7", "10", "13"]
3: (5) ["X", "3", "6", "9", "12"]

Modified Output

0:(5) ["1", "X", "8", "11", "15"]
1: (5) ["2", "5", "X", "X", "14"]
2: (5) ["X", "4", "7", "10", "13"]
3: (5) ["X", "3", "6", "9", "12"]

You can achieve this by iterating through each array using forEach method.

a.forEach((item) => {

   if (item === "1")
      item = "2"
   else
      if (item === "2")
          item = "1"
})

Answer 6

Based on the provided sample, it seems like you should switch between 1 and 2.

Example

0: (5) ["2", "X", "8", "11", "15"] 
1: (5) ["1", "5", "X", "X", "14"]
2: (5) ["X", "4", "7", "10", "13"]
3: (5) ["X", "3", "6", "9", "12"]

Modified Output

0:(5) ["1", "X", "8", "11", "15"]
1: (5) ["2", "5", "X", "X", "14"]
2: (5) ["X", "4", "7", "10", "13"]
3: (5) ["X", "3", "6", "9", "12"]

You can achieve this by iterating through each array using forEach method.

a.forEach((item) => {

   if (item === "1")
      item = "2"
   else
      if (item === "2")
          item = "1"
})

I desire to rearrange the items within several arrays of lists

Answer №1

Answer №2

Answer №3

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