newbies
newbies

Reputation: 13

Insert 1 value in 2d array in javascript

I need some help with my code. I try to insert only one value in each array. I need to fill in the row first and after that, if the row is full then move to the next column. I try to solve this part for a couple of days but I fail. So here is my code

const testData = [1,2,3,4,5,6,7,8,9];                
const create2dArray = (row, column) => {
                    var result = [];
                    for(let i = 0; i< row; i++){
                        result[i]= [];
                        for(let j = 0; j<column; j++){   
                            result[i][j] = [];
                            for(let e = 0; e < testData.length; e++){
                            result[i][j] = [testData[e]];
                            }
                        }
                    }
                    return result;
            
                }
            let Column = 5
            let Row = 5
            filterQuotaData(EnrollmentQuota);
            var ground = create2dArray(Column,Row);
            console.log(ground);

Suppose the output is :

[1],[2],[3],[4],[5]
[6],[7],[8],[9],[]
[],[],[],[],[]
[],[],[],[],[]
[],[],[],[],[]

instead, I got:

[9],[9],[9],[9],[9]
[9],[9],[9],[9],[9]
[9],[9],[9],[9],[9]
[9],[9],[9],[9],[9]
[9],[9],[9],[9],[9]

I hope someone can help me to solve this problem

Upvotes: 1

Views: 64

Answers (2)

zer00ne
zer00ne

Reputation: 44118

What's happening in your code is that you have the 3rd loop adding everything to each column from 2nd loop. The reason why they are all 9s is because you are overwriting each column by using an assignment instead of adding it to the array:

// 3rd loop
array[0][0][0] = 1 // 1st iteration [[[1],...]]
array[0][0][1] = 2 // 2nd iteration [[[2],...]]

Here's an example that uses 2 loops and pushes sub-arrays and shifts from test array.

const test = [1, 2, 3, 4, 5, 6, 7, 8, 9];
const create2dArray = (row, column) => {
  let result = [];
  for (let r = 0; r < row; r++) {
    result.push([]);
    for (let c = 0; c < column; c++) {
      let data = test.length < 1 ? [] : [test.shift()]
      result[r].push(data);
    }
  }
  return result;
}
let row = 5, col = 5;

let ground = create2dArray(row, col);
console.log(JSON.stringify(ground));

Upvotes: 0

dudung
dudung

Reputation: 719

Following code

const testData = [1,2,3,4,5,6,7,8,9];                
const create2dArray = (row, column) => {
                    var result = [];
                    k = 0
                    for(let i = 0; i< row; i++){
                        result[i]= [];
                        for(let j = 0; j<column; j++){   
                            if(k < testData.length) {
                              result[i][j] = [testData[k]];
                            } else {
                              result[i][j] = [];
                            }
                            k++
                        }
                    }
                    return result;
            
                }
            let Column = 5
            let Row = 5
            //filterQuotaData(EnrollmentQuota);
            var ground = create2dArray(Column,Row);
            console.log(ground);

produces

[
  [ [ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ] ],
  [ [ 6 ], [ 7 ], [ 8 ], [ 9 ], [] ],
  [ [], [], [], [], [] ],
  [ [], [], [], [], [] ],
  [ [], [], [], [], [] ]
]

Does it what you need?

Upvotes: 1

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