Java Problem

debo · 27-03-2008 01:30PM #1

I have a print statement with surname, forename and number as Strings

System.out.println(surname + ", " + forename + "\t" + number);

But I need to get into two lef aligned columns one with suname and forename and the other with number. I'm not quite sure how printf works. Could anyone help?

dzy · 27-03-2008 02:25PM

debo wrote: »
I have a print statement with surname, forename and number as Strings
System.out.println(surname + ", " + forename + "\t" + number);
But I need to get into two lef aligned columns one with suname and forename and the other with number. I'm not quite sure how printf works. Could anyone help?

I don't understand. Isn't this exactly what your code is doing?

class PersonLister
{
    public static void main(String[] args)
    {
        String forename = "Joe";
        String surname = "Soap";
        int number = 1;

        for (int i = 0; i < 10; i++)
        {
            System.out.println(surname + ", " + forename + "\t" + number);
        }
    }    
}

Creamy Goodness · 27-03-2008 02:29PM

to do a line like this

System.out.println(surname + ", " + forename + "\t" + number);

i think you need to override the toString() method for your class as number is of type int and you're concatinating it on to a string (my java is really rusty).

dzy · 27-03-2008 02:33PM

Cremo wrote: »

to do a line like this

System.out.println(surname + ", " + forename + "\t" + number);

i think you need to override the toString() method for your class as number is of type int and you're concatinating it on to a string (my java is really rusty).

Java's clever like that and will automatically convert the integer to a String when concatenating.

fergalr · 27-03-2008 02:51PM

I think he's asking a question about printf from reading his post. Not println.

If you want to do alignment in a big way (more than you already have in your original post), you probably do want to be using printf... best just look up the docs with it and learn how it works.
It's a bit tricky to get used to place holders and stuff when you've only used println, but spend a little time and it becomes clear...

Edit:

At least, that's what I'm assuming based on

I'm not quite sure how printf works.

You probably want to read this stuff:
http://java.sun.com/j2se/1.5.0/docs/api/java/util/Formatter.html#syntax
or maybe look for an introduction to C printf as that might be a bit more comprehensible...

http://java.sun.com/j2se/1.5.0/docs/api/java/io/PrintStream.html#printf(java.util.Locale,%20java.lang.String,%20java.lang.Object...)

fergalr · 27-03-2008 03:11PM

Here, you're looking for something like this:

PrintStream p = new PrintStream(System.out);
p.printf("%-20s%-20s%-20d","firstname","lastname",10);

or maybe:

PrintStream p = new PrintStream(System.out);

String firstname = "Dave";
String lastname = "Johnson";
int age = 25;
String firstColString = lastname + "," + firstname;

p.printf("%-20s%-20d",firstColString,age);

To answer your question more exactly..?

Java Problem

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