2Dmatrix90Deg
JavaScript
function mat(a){
return a.map((row,i)=>{ return row.map((val,j)=>{ return a[a.length-1-j][i]})})
}
console.log(mat([[1,2,3],[4,5,6],[7,8,9]]));
// to change in place map return new array
function mat1(matrix){
matrix.reverse();
for(let i=0;i<matrix.length;i++)
for(let j=i;j<matrix[i].length;j++)
[matrix[i][j],matrix[j][i]] = [matrix[j][i],matrix[i][j]]
return matrix;
}
console.log('**',mat1([[1,2,3],[4,5,6],[7,8,9]]));