CODEWITHSUNDEEP
javaarraysloopsmultidimensional-arrayformatting
Not Steve
Not Steve

Reputation: 127

Can someone help me with formatting a two-dimensional array display with a for loop in java

I'm trying to code a for loop to display a two-dimensional array of doubles rounded to one decimal place. However, whenever I run my code it displays only the last column of data correctly, and displays the preceding columns with two extra decimal points. Here is my code:

public void calcDistance(double [] radians, int [] initialVelocity, double [][] answers)
{

    for(int rowIndex = 0; rowIndex < initialVelocity.length; rowIndex++)
    {
        for(int colIndex = 0; colIndex < radians.length; colIndex++)
        {
            answers[rowIndex][colIndex] = ((Math.pow(initialVelocity[rowIndex], 2) * Math.sin(radians[colIndex]))/ 9.8);
            System.out.print(initialVelocity[rowIndex] + " ");                
            System.out.printf("%9.1f", answers[rowIndex][colIndex]);
        }
        System.out.println();
    }
}

And it displays something like this:

20      17.220      20.420      23.420      26.220      28.920      31.3
25      27.025      31.925      36.625      41.025      45.125      48.9
30      38.830      45.930      52.730      59.030      64.930      70.4
35      52.835      62.535      71.735      80.335      88.435      95.8
40      69.040      81.640      93.640     104.940     115.440     125.1
45      87.345     103.345     118.545     132.845     146.145     158.3
50     107.850     127.650     146.350     164.050     180.450     195.4

Why do some numbers have 3 digits after the decimal point?

Upvotes: 1

Views: 49

Answers (1)

luk2302
luk2302

Reputation: 57114

You should change your for-loop to be:

for(int rowIndex = 0; rowIndex < initialVelocity.length; rowIndex++)
{
    System.out.print(initialVelocity[rowIndex] + " ");                
    for(int colIndex = 0; colIndex < radians.length; colIndex++)
    {
        answers[rowIndex][colIndex] = ((Math.pow(initialVelocity[rowIndex], 2) * Math.sin(radians[colIndex]))/ 9.8);
        System.out.printf("%9.1f ", answers[rowIndex][colIndex]);
    }
    System.out.println();
}

What previously happened is that you output the following in that exact order:

20[space]
17.2
20[space]
20.4
20[space]
etc.

Those appended to one another yield

20 17.220 20.420 etc.

You should print the initialVelocity only once per line - at the beginning before the inner loop runs. the inner loop-values have to separated with a space.

Upvotes: 2

Related Questions