Create evenly spaced numbers in a table

Question

I have used TreeMaps to calculate the frequencies of letters in user-entered text. When displaying these frequencies I get quite a messy output as some frequencies are zero, and others are numbers to one or two decimal places.

An example, from entering Harry :

Letter |a |b |c |d |e |f |g |h |i |j |k |l |m |n |o |p |q |r |s |t |u |v |w |x |y |z |
Count  |0.2 |0 |0 |0 |0 |0 |0 |0.2 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0.4 |0 |0 |0 |0 |0 |0 |0.2 |0 |

How do I produce a table which is neatly spaced (and without knowing the frequencies), like this:

Letter |a   |b |c |d |e |f |g |h   |i |j |k |l |m |n |o |p |q |r   |s |t |u |v |w |x |y   |z |
Count  |0.2 |0 |0 |0 |0 |0 |0 |0.2 |0 |0 |0 |0 |0 |0 |0 |0 |0 |0.4 |0 |0 |0 |0 |0 |0 |0.2 |0 |

To produce my table I have used simple for loops which increment through the Treemap , and I was thinking of the System.out.format command, but I'm still learning a lot about java so this would probably be wrong.

My for loops are here:

System.out.print("Letter |");
for (char a: Allmap.keySet()) {
  System.out.print(a + " |");
}

System.out.print("\n" + "Count  |");
for (double b: Allmap.values()) {
  System.out.print(df.format(b / CHARCOUNT) + " |");
}

Answer 1

I assume you want something like this, although I haven't had time to test it.

System.out.print("Letter |");
for (char a : Allmap.keySet()) {
    System.out.print(a + " |");
}

System.out.print("\nCount  |");
for (double b : Allmap.values()) {
    System.out.printf( "%.2f |", d );
}

Also note that this code will round the double to two decimal places, so 3.14159 becomes 3.14 , and 2.71828 becomes 2.72 .

Also, here was my source for rounding a double to two decimal places: Round a double to 2 decimal places