Need some help with very basic Java.

[Cacao]

Hey guys, so here's what I have to do:

 

Write a program that will round a value in a double value to one tenth, eg. the value 3.14 is rounded to 3.1

 

Can anyone help me out with this? Do I need to convert the double into some other data type in order to round it?

 

 

Obviously this will just output 3.14, I'm assuming I need to something like --->  var1 = (IDK WHAT TO PUT HERE) 3.14;

 

Thanks!

[Quest]

There sure seems to be a lot of talk on this forum about how people seem to understand what goes into code and such...

Not seeing any of it at work here

Leave it to the kid making music, then.

 

The best I can think of is something like;

double var1 = 3.14;
System.out.println(var1); // var1 is 3.14

int decimalPlaces = 2;
BigDecimal bd = new BigDecimal(var1);

// setScale is immutable
bd = bd.setScale(decimalPlaces, BigDecimal.ROUND_HALF_UP);
var1 = bd.doubleValue();

System.out.println(var1); // var1 is 3.1

/qb

I apologize if this is just an abomination of crap, I have touched java in a couple years, since running RuneScape private servers

[Cacao]

There sure seems to be a lot of talk on this forum about how people seem to understand what goes into code and such...

Not seeing any of it at work here

Leave it to the kid making music, then.

 

The best I can think of is something like;

double var1 = 3.14;

System.out.println(var1); // var1 is 3.14

int decimalPlaces = 2;

BigDecimal bd = new BigDecimal(var1);

// setScale is immutable

bd = bd.setScale(decimalPlaces, BigDecimal.ROUND_HALF_UP);

var1 = bd.doubleValue();

System.out.println(var1); // var1 is 3.1

/qb

I apologize if this is just an abomination of crap, I have touched java in a couple years, since running RuneScape private servers

Thanks for your reply, but that's quite a bit more advanced than me I think the solution is much easier. 

 

Plus your program just gives me a bunch of errors when I try to compile it D:

[Student]

i'd do it like this

System.out.println(((double) Math.round(3.14 * 10)) / 10);

[Quest]

Thanks for your reply, but that's quite a bit more advanced than me I think the solution is much easier. 

 

Plus your program just gives me a bunch of errors when I try to compile it D:

Ohhhhhhhhhhhhhhh! You're doing the think from school, aren't you! Dude, had the same worksheet in my game design class that I was in for a few weeks last year.

Let me try a couple things. Again, no promises, but I may come up with something. It's cool to work with Java again

[Quest]

 

i'd do it like this

System.out.println(((double) Math.round(3.14 * 10)) / 10);

It could very well be that simplistic.

Dhuurrr on my part.

[Cacao]

It could very well be that simplistic.

Dhuurrr on my part.

 

 

i'd do it like this

System.out.println(((double) Math.round(3.14 * 10)) / 10);

Thanks man, that totally worked!

[Cacao]

Ohhhhhhhhhhhhhhh! You're doing the think from school, aren't you! Dude, had the same worksheet in my game design class that I was in for a few weeks last year.

Let me try a couple things. Again, no promises, but I may come up with something. It's cool to work with Java again

I'm doing a Grade 12 Computer Programming course with the Canadian Online Highschool

[wolfsinner]

I know it's been answered, but if your sole purpose is to print this rounded double, this will suffice.

 

double var = 3.14;System.out.printf("%.1f\n", var);