rotateImage leetcode and codesignal

rotateImage.ts

function rotateImage(a: number[][]): number[][] {
    swap(a)
           reflext90(a)
           return a
           }

function swap(a:number[][]):void{
    let row=a.length;
  let col=a[0].length;
  for(let i = 0; i < row; i ++) {
         for(let j = i + 1; j < col; j ++) {
           
      const temp = a[j][i]
            a[j][i] = a[i][j]
            a[i][j] = temp
}}}
function reflext90(matrix:number[][]):void{
 const n= matrix.length
    for (let i = 0; i < matrix.length; i++){
        for (let j = 0; j < matrix.length/2; j++){
            const temp = matrix[i][j]
            matrix[i][j] = matrix[i][n- j -1]
            matrix[i][n - j -1] = temp
        }
    }}