Java printf formatting to print items in a table or columns

问题

I am wanting to print things in a neat columns using printf.

happening       0.083333    [4]
hi              0.083333    [0]
if              0.083333    [8]
important       0.083333    [7]
is              0.250000    [3, 5, 10]
it              0.166667    [6, 9]
tagged          0.083333    [11]
there           0.083333    [1]
what            0.083333    [2]

I have this code System.out.printf("%s %.6f %s \n", word, web.getFrequency(word), loc);, but it prints out this:

happening  0.083333  [ 4 ] 
hi  0.083333  [ 0 ] 
if  0.083333  [ 8 ] 
important  0.083333  [ 7 ] 
is  0.250000  [ 3 5 10 ] 
it  0.166667  [ 6 9 ] 
tagged  0.083333  [ 11 ] 
there  0.083333  [ 1 ] 
what  0.083333  [ 2 ]

Any help would be appreciated.

回答1:

I would use this:

System.out.printf ("%-30s %1.7f %s%n", word, etc, etc2);

回答2:

You can get the max length of all the word strings, and store that length in a variable, max. Use a for loop to get that max, and then create a String that has the format with concatenating the normal printf format with the max variable to be used as the width. Additionally \t puts in a tab character.

int max = 0;
for (int ii = 0; ii < numberOfStrings; ii++)
{
   max = (word.length() > max) ? word.length() : max;
}
String format = "%" + max + "s\t%.6f\t%s \n";
System.out.printf(format, word, web.getFrequency(word), loc);

回答3:

System.out.format("%-8s%-8s%-8s\n","a","b","pow(b,a)");
System.out.format("%-8d%-8d%-8d\n",1,2,1);
System.out.format("%-8d%-8d%-8d\n",2,3,8);
System.out.format("%-8d%-8d%-8d\n",3,4,81);
System.out.format("%-8d%-8d%-8d\n",4,5,1024);
System.out.format("%-8d%-8d%-8d\n",5,6,15625);

//the negative integer kinda sets it back to the number of space needed

回答4:

input:

happening       0.083333    [4]
hi              0.083333    [0]
if              0.083333    [8]
important       0.083333    [7]
is              0.250000    [3, 5, 10]
it              0.166667    [6, 9]
tagged          0.083333    [11]
there           0.083333    [1]
what            0.083333    [2]

code:

import java.util.Scanner;
public class MyClass { 
    private static final Scanner sc = new Scanner(System.in);
       public static void main(String args[]) {
            for(int i = 0 ; i < 9; i++){
                String str = sc.next();
                float f = sc.nextFloat();
                String str2 = sc.nextLine();
                System.out.printf("%-10s %f %s\n", str, f, str2);
             }
             sc.close();
      }   
  }

output:

happening       0.083333    [4]
hi              0.083333    [0]
if              0.083333    [8]
important       0.083333    [7]
is              0.250000    [3, 5, 10]
it              0.166667    [6, 9]
tagged          0.083333    [11]
there           0.083333    [1]
what            0.083333    [2]

use - to make the string left aligned, use field width to align them properly. In your case printf statement will be

System.out.printf("%-10s %.6f %s\n", word, web.getFrequency(word), loc);

来源：https://stackoverflow.com/questions/33466526/java-printf-formatting-to-print-items-in-a-table-or-columns

标签

java

printf

multiple-columns