Java System.out.print formatting

问题

Here is my code (well, some of it). The question I have is, can I get the first 9 numbers to show with a leading 00 and numbers 10 - 99 with a leading 0.

I have to show all of the 360 monthly payments, but if I don't have all month numbers at the same length, then I end up with an output file that keeps moving to the right and offsetting the look of the output.

System.out.print((x + 1) + "  ");  // the payment number
System.out.print(formatter.format(monthlyInterest) + "   ");    // round our interest rate
System.out.print(formatter.format(principleAmt) + "     ");
System.out.print(formatter.format(remainderAmt) + "     ");
System.out.println();

Results:

8              $951.23               $215.92         $198,301.22                         
9              $950.19               $216.95         $198,084.26                         
10              $949.15               $217.99         $197,866.27                         
11              $948.11               $219.04         $197,647.23

What I want to see is:

008              $951.23               $215.92         $198,301.22                         
009              $950.19               $216.95         $198,084.26                         
010              $949.15               $217.99         $197,866.27                         
011              $948.11               $219.04         $197,647.23

What other code do you need to see from my class that could help?

回答1:

Since you're using formatters for the rest of it, just use DecimalFormat:

import java.text.DecimalFormat;

DecimalFormat xFormat = new DecimalFormat("000")
System.out.print(xFormat.format(x + 1) + " ");

Alternative you could do whole job in whole line using printf:

System.out.printf("%03d %s  %s    %s    \n",  x + 1, // the payment number
formatter.format(monthlyInterest),  // round our interest rate
formatter.format(principleAmt),
formatter.format(remainderAmt));

回答2:

Since you are using Java, printf is available from version 1.5

You may use it like this

System.out.printf("%03d ", x);

For Example:

System.out.printf("%03d ", 5);
System.out.printf("%03d ", 55);
System.out.printf("%03d ", 555);

Will Give You

005 055 555

as output

See: System.out.printf and Format String Syntax

回答3:

Use System.out.format

回答4:

Something likes this

public void testPrintOut() {
    int val1 = 8;
    String val2 = "$951.23";
    String val3 = "$215.92";
    String val4 = "$198,301.22";
    System.out.println(String.format("%03d %7s %7s %11s", val1, val2, val3, val4));

    val1 = 9;
    val2 = "$950.19";
    val3 = "$216.95";
    val4 = "$198,084.26";
    System.out.println(String.format("%03d %7s %7s %11s", val1, val2, val3, val4));
}

回答5:

Are you sure that you want "055" as opposed to "55"? Some programs interpret a leading zero as meaning octal, so that it would read 055 as (decimal) 45 instead of (decimal) 55.

That should just mean dropping the '0' (zero-fill) flag.

e.g., change System.out.printf("%03d ", x); to the simpler System.out.printf("%3d ", x);

回答6:

Just use \t to space it.

Example:

System.out.println(monthlyInterest + "\t")

//as far as the two 0 in front of it just use a if else statement. ex: 
x = x+1;
if (x < 10){
    System.out.println("00" +x);
}
else if( x < 100){
    System.out.println("0" +x);
}
else{
    System.out.println(x);
}

There are other ways to do it, but this is the simplest.

来源：https://stackoverflow.com/questions/9849800/java-system-out-print-formatting

标签

java

format