System.out.println doesn't print a line with no parameters?

Question

public class Test2 {
    public static void mystery(int x, int y, boolean b, String s) {
        System.out.println(x*3 + "..." + x/y);
        if (b)
            System.out.println("yes");
        else
            System.out.println("no");
        for (int i = 2; i <= 5; i++)
            System.out.print(2*i);
        System.out.println();
        System.out.println((double)(y/x));
        System.out.println(s.substring(3,7));
     } // end mystery

     public static void main(String[] args) {
         mystery(7,3,true,"freezing");
     }
}

I'm a little confused and I think I'm missing something. How come the output of the for loop in this code is 46810? Shouldn't there be a line in between each of the numbers?

If you mean the second `Sysout` after `for` loop, then you need to have braces with your loop. — Rohit Jain, Apr 18 '15 at 06:06
Kind of a duplicate of http://stackoverflow.com/q/8020228/ - you would do well to read this, especially Jon Skeet's answer. — Dawood ibn Kareem, Apr 18 '15 at 07:19

score 3 · Answer 1 · answered Apr 18 '15 at 06:07

It appears to me that you wanted your loop to look like this:

for (int i = 2; i <= 5; i++)
 System.out.print(2*i);
 System.out.println();

But the for only applies to the first statement. To include multiple statements in the loop, you need to enclose the loop body in curly braces:

for (int i = 2; i <= 5; i++) {
 System.out.print(2*i);
 System.out.println();
}

It's best to always use curly braces when writing a for loop, and also while, do, if, and else, even though the language allows you to have a body of just one statement without the curly braces. For example:

 if (b) {
     System.out.println("yes");
 } else {
     System.out.println("no");
 }

Elliott Frisch · Answer 2 · 2015-04-18T06:06:16.067

1

Not with System.out.print(2 * i);. For the output you seem to expect change it to,

System.out.println(2 * i);

or add braces to your for loop like,

for (int i = 2; i <= 5; i++){
    System.out.print(2*i);
    System.out.println();
}

Java loops aren't controlled by indentation, you need braces to contain more than one line.

edited Apr 18 '15 at 06:06

answered Apr 18 '15 at 06:05

Elliott Frisch

198,278
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But there's a println() right after it. Wouldn't that skip a line? – aaa Apr 18 '15 at 06:05
@aaa Only if that `println` call was part of the loop. – Elliott Frisch Apr 18 '15 at 06:06
1

@aaa Yes, it skips a line--_after the entire loop is done_. Not in between every number. – ajb Apr 18 '15 at 06:08

score 1 · Answer 3 · answered Apr 18 '15 at 06:08

Try this:

for (int i = 2; i <= 5; i++)
{
    System.out.print(2*i);
    System.out.println();
    System.out.println((double)(y/x));
    System.out.println(s.substring(3,7));
}

When you are using the for loop then it is recommended to put the code inside it in the curly braces {}.

score 0 · Answer 4 · answered Apr 18 '15 at 06:07

0

The for loop logic must be contained in {}

answered Apr 18 '15 at 06:07

Jakir00

2,023
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System.out.println doesn't print a line with no parameters?

4 Answers4