how to use printf in java

Question

I have a question on how to use printf. In my case, I don't know how to use printf to make my headings of my table (two dimensional array) match the table's alignment. I want it so that the headings numbers will be in line with the numbers inside the table. How can I fix this? Any help will be greatly appreciated. Below is my output:

run:
                         Projectile Distance (Feet)

MPH   572.95780   630.25357   687.54935   744.84513   802.14091  2291.83118
____________________________________________________________________________________

45    42.3390045    44.8135645    38.8776945    25.6454145     7.6001045    44.20434
67    63.0380667    66.7224167    57.8845667    38.1831767    11.3157167    65.81535
77    72.4467377    76.6809877    66.5240577    43.8821577    13.0046277    75.63853
89    83.7371389    88.6312689    76.8914489    50.7209389    15.0313289    87.42636
90    84.6779990    89.6271290    77.7553890    51.2908390    15.2002190    88.40867
56    52.6885356    55.7679956    48.3811356    31.9142956     9.4579156    55.00984
99    93.1457999    98.5898399    85.5309299    56.4199199    16.7202399    97.24954
BUILD SUCCESSFUL (total time: 0 seconds)

Below is my code for the two files:

public class CatapultTester {

static int velocity[] = {45, 67, 77, 89, 90, 56, 99};
static double angle[] = {Math.toDegrees(10), Math.toDegrees(11), Math.toDegrees(12), 
Math.toDegrees(13), Math.toDegrees(14), Math.toDegrees(40)};

public static void main(String args[]){

    System.out.printf("%55s", "Projectile Distance (Feet)");
    System.out.println("\n");
    System.out.printf("%1s", "MPH");
    for(int k = 0; k < angle.length; k++){
        System.out.printf("%12.5f", angle[k]);
    }
    System.out.println();
    System.out.println("___________________________________________________"
            + "_________________________________");
    System.out.println();
    Catapult.display(angle, velocity);

}

}

_

public class Catapult {

public static void display(double angle[], int velocity[]){
    double[][] result = new double[velocity.length][angle.length];
    for(int i = 0; i < velocity.length; i++){
        for(int j = 0; j < angle.length; j++){
            result[i][j] = velocity[i] * Math.sin(angle[j] / 9.8);
            System.out.printf("%1d%12.5f", velocity[i], result[i][j]);
        }
        System.out.println();
    }
}
}

Christian Tapia · Accepted Answer · 2014-01-05 02:19:56Z

In the display method, you are printing the MPH value for each element in a line, you must print it just one time:

public static void display(double angle[], int velocity[])
{
    double[][] result = new double[velocity.length][angle.length];
    for (int i = 0; i < velocity.length; i++) {
        System.out.print(velocity[i] + " "); // Print once per line, and add extra space to align correctly
        for (int j = 0; j < angle.length; j++) {
            result[i][j] = velocity[i] * Math.sin(angle[j] / 9.8);
            System.out.printf("%12.5f", result[i][j]);
        }
        System.out.println();
    }
}

Output:

                             Projectile Distance (Feet)

MPH   572,95780   630,25357   687,54935   744,84513   802,14091  2291,83118
____________________________________________________________________________________

45     42,33900    44,81356    38,87769    25,64541     7,60010    44,20434
67     63,03806    66,72241    57,88456    38,18317    11,31571    65,81535
77     72,44673    76,68098    66,52405    43,88215    13,00462    75,63853
89     83,73713    88,63126    76,89144    50,72093    15,03132    87,42636
90     84,67799    89,62712    77,75538    51,29083    15,20021    88,40867
56     52,68853    55,76799    48,38113    31,91429     9,45791    55,00984
99     93,14579    98,58983    85,53092    56,41991    16,72023    97,24954

Krazick · Accepted Answer · 2014-01-05 02:14:30Z

0

Your header loop uses %12.5f format for each number

Your display method loop uses %1d%12.5f format for two numbers. Match them up and they should align better.

answered Jan 5, 2014 at 2:14

Krazick

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