LearnStreet Sample Solution Sudoku Solver Project Method 6

function isCorrectColumn(sudoku, col) {
    // This method should return true if all the numbers from 1 to 9
    // are present in the column indexed by the 'col' argument in the
    // 'sudoku' puzzle. It should return false if the column is incomplete
    // or has duplicates.
    // This method is analogous to the isCorrectRow() method above.
    // REPLACE THIS CODE WITH YOUR isCorrectColumn() METHOD
    var returnValue = true;
    var colCopy = [];
    for(var i=0; i<9; i++){
        colCopy[i] = sudoku[i][col];
    }
    colCopy.sort();
    for(var i=1; i<=9; i++){
        if(colCopy[i-1]!==i){
            returnValue = false;
        }
    }
    return returnValue;
}