printf

[abalfazl hossein]

It is said about flags in pritf in SCJP book,page 507

"+" Include a sign (+ or -) with this argument

int i2=12345;
        System.out.printf("%d\n",i2);
        System.out.printf("%+d\n",i2);

I don't think this flag"+" could print negative numbers as book said.Which flag can print negative sign?


Another question:

int i1 = -123;
int i2 = 12345;
System.out.printf(">%1$(7d< \n", i1);
System.out.printf(">%0,7d< \n", i2);
System.out.format(">%+-7d< \n", i2);

about this line:

System.out.format(">%+-7d< \n", i2);

What do this mean: +-7?

When I try

        int i2=12345;
        System.out.printf("%d\n",i2);
        System.out.printf("%+-d\n",i2);

It throws exception.

[Tony Docherty]

abalfazl hossein wrote:
"+" Include a sign (+ or -) with this argument

int i2=12345;
        System.out.printf("%d\n",i2);
        System.out.printf("%+d\n",i2);

I don't think this flag"+" could print negative numbers as book said.Which flag can print negative sign?

Why not try it with a negative number and see what happens.

System.out.format(">%+-7d< \n", i2);

What do this mean: +-7?

The '+' does as detailed above, it appends a sign character to the number.
The '-7' means pad to 7 characters and left align, specifically '-' means left align but this is only meaningful if you specify a width to pad the number to (numbers are naturally right aligned), hence you get an exception if you use it without a width.

[Campbell Ritchie]

Don't use \n even if you found it in your book. Always use %n
You can find all the tags in the Formatter class. Beware: there are many many different tags.

[Campbell Ritchie]

You always get some sort of sign of a number being negative. What the + option means is it prints a sign when the number is positive, too.

[Paweł Baczyński]

Campbell Ritchie wrote:You always get some sort of sign of a number being negative. What the + option means is it prints a sign when the number is positive, too.

Or zero.

[Campbell Ritchie]

Forgot about zero. Thank you.

[sai rama krishna]

In the real world coding i never come across these kind of scenarios SCJP asks