Autoboxing

[p0o0o0ya]

hi guys.
what' s up?
I wrote this program:

//: object/E9
public class E9{
	public static void main(String[ ] args){
		Boolean  Bo= true;
		boolean  bo= Bo;
		System.out.println("Boolean = " + Bo);
		System.out.println("boolean = " + bo); 
		Character Ch='a';
		char ch=Ch;
		System.out.println("Character = " + Ch);
		System.out.println("char = " + ch); 
		Byte By=1;
		byte by=By;
		System.out.println("Byte = " + By);
		System.out.println("byte = " + by); 
		Short Sh=2;
		short sh=Sh;
		System.out.println("Short = " + Sh);
		System.out.println("short = " + sh); 
		Integer I=3;
		int i=I;
		System.out.println("Integer = " + I);
		System.out.println("int = " + i); 
		Long L=64;
		long l=L;
		System.out.println("Long = " + L);
		System.out.println("long = " + l); 
		Float F=5.1;
		float f=F;
		System.out.println("Float = " +F);
		System.out.println("float = " + f); 
		Double D=6.1;
		double d=D;
		System.out.println("Boolean = " +Bo);
		System.out.println("boolean = " + bo); 
	}
}//~

and compiler give me this error:
***
E9.java:24: incompatible types
found : int
required: java.lang.Long
Long L=64;
^
E9.java:28: incompatible types
found : double
required: java.lang.Float
Float F=5.1;
^
2 errors
****
what's wrong with my program?
thanks.

[baloda]

initialize Long like
Long L=64L; in place of Long L=64;

initialize Float like
Float F=5.1F; in place of Float F=5.1; this is the right way.

good Luck!!

[mine0926]

First java is case sensitive so it should be
long not Long
and
float not Float

Second, declaring float's value should have f on its ending.

float aFloatType = 12.25f

[pbrockway2]

E9.java:24: incompatible types
found   : int
required: java.lang.Long
                Long L=64;
                       ^
E9.java:28: incompatible types
found   : double
required: java.lang.Float
                Float F=5.1;
                        ^
2 errors

In both cases the compiler means what it says. You attempted to assign int and double values (the literals 64 and 5.1) but the compiler demands long and float values when assigning to Long and Float variables.

To elaborate a little, from the Java Language Specification...

Regarding integer literals: "An integer literal is of type long if it is suffixed with an ASCII letter L or l (ell); otherwise it is of type int". And for floating point literals: "A floating-point literal is of type float if it is suffixed with an ASCII letter F or f; otherwise its type is double and it can optionally be suffixed with an ASCII letter D or d."

Assignment always involves an assignment conversion. As indicated there, such conversions come in various flavours. Of interest here is the allowed possibility of a boxing conversion. The options are limited and enumerated: int->Long and double->Float are not mentioned.

[baloda]

First java is case sensitive so it should be
long not Long
and
float not Float

Second, declaring float's value should have f on its ending.

float aFloatType = 12.25f

'Float' is also valid Floating point data type check out java.lang.Float. and u r also ignoring error msg.

@p0o0o0ya go with as i mentioned.

[p0o0o0ya]

First java is case sensitive so it should be
long not Long
and
float not Float
[/code]

ok. I know that java is case sensitive but,
long is a primitive
and Long is a wrapper type.