programming help (1 Viewer)

[phizz]

Just a bit of a mind blank at the moment, firstly I'm programming in Java, but any algorithm solution will help.

Basically I want to store the decimal value from a real varible, eg:

526.78

I want to be able to store 0.78 sepperatly.

so far its programmed like:

double num; (num is then inputted by user)

double decimal; (place to store decimal value of num)

any help will be very much appreciated - phizz

 

[sunny]

1) Floor the input number
2) Subtract it from the original number
3) You're left with the decimal

 

[jm1234567890]

or

cast into string
delete bits before decimal point
cast back to double

lol, gotta love how simplistic it is to play around with strings in java.

 

[jonathan109]

Cast the double to a String.

Invoke a indexof method call passing in ".".

Sub string it and cast it back into the appropriate format.

Since you're splitting it up, they're both going to be integer's so store them both back into integers.

 

[poloktim]

Cast the double to a String.

Invoke a indexof method call passing in ".".

Sub string it and cast it back into the appropriate format.

Since you're splitting it up, they're both going to be integer's so store them both back into integers.

Agreed here. If memory serves me correctly, doubles are the size of two words (sixty-four bits), so storing two doubles means you've got one hundred and twenty-eight bits. Storing as two integers (thirty-two bits) means you've only used up half that (sixty-four bits).

Of course that's just for thrity-two bit systems (though Java may be standard even for the better sixty-four bit machines). Anyone with a G5/AMD64/Intel equivalent able to check?

 

[phizz]

hey thanks guys, I'll give it a go!

 

[sunny]

Of course that's just for thrity-two bit systems (though Java may be standard even for the better sixty-four bit machines). Anyone with a G5/AMD64/Intel equivalent able to check?

Bit width is fixed by the JVM.

 

[poloktim]

Bit width is fixed by the JVM.

Yes, but is the VM different on sixty-four bit machines?

 

[jm1234567890]

Yes, but is the VM different on sixty-four bit machines?

no, VM is standard, which is why code is portable

 

[poloktim]

no, VM is standard, which is why code is portable

Thanks.

That's a bit of a kick up the bum for sixty-four bit machines though. The VM isn't utilising the computer's full potential.

 

[jm1234567890]

Thanks.

That's a bit of a kick up the bum for sixty-four bit machines though. The VM isn't utilising the computer's full potential.

nah, if the vm is programmed well, it could