long with l , float with f, double with d

[susan waters]

When we declare a long variable

long l1 = 100l -> this l after 100 (Pl note this is NOT thousand this 100 and an l)
why we need to type l after the actual value since we already declared it's a long type ? Similaraly for double and float.

thanks very much for the reply.

- Susan

[wise owen]

1) All three integer literals (decimal, hexadecimal, octal) are defined as int by default, but you can specify a long integer by putting an 'L' or 'l' after the number.

2) The int value range is -(2^31) to (2^31)-1 [-2,147,483,648 to 2,147,483,647]. you do not need "L" or "l" if the value in the int value
range.

3) A series of digits with a decimal point is of type double. Float numbers have the f or F suffix. Double numbers have d or D. If no suffix is provided, the default double type is assumed.

[Naseem Khan]

By default, int literals are 32 bits.

100 is 32 bit of size. When you put l or L (lowercase L or uppercase), then it will be 64 bit long.

Similary floating point no. say 32.4 is by default 64 bit double literal.

32.4--->>> 64 bit double literal

32.4d or 32.4D ---->>> 64 bit size

32.4f or 32.4F ---->>> 32 bit size


Regards


Naseem Khan
[ June 17, 2006: Message edited by: Naseem Khan ]

[susan waters]

Thanks very much for the replys.
But I have a question here.

As you all said 32.4 by default 64 bit. What is the advantage of converting to 32 bit like 32.4F or 32.4f

similaraly integer,
you all said , for example 39 is integer literal of 32 bit size. When I say 39l or 39L it will be 64 bit. What advantage I get when I convert it to 64 bit by placing L or l as a sufix.

thanks very much for reply.

[Naseem Khan]

As you all said 32.4 by default 64 bit. What is the advantage of converting to 32 bit like 32.4F or 32.4f

For long its fine

long l=45; Is correct. 32 bit size can be asssigned to long which is 64 bit of size.

but take this case..

float f=45.8; // will this compile. Surely not. 64 bit can't be assigned to 32 bit type.


So what will you do? You have to put suffix f or F here.

float f=45.8f or 45.8F;


Regards


Naseem
[ June 18, 2006: Message edited by: Naseem Khan ]

[susan waters]

Thanks Naseem for your nice explonation. I clearly understand the concept. Thanks
Susan

[Shiaber Shaam]

Is adding a L or l to specify long is mandatory.. or it is optional....

[S Thiyanesh]

long v1 = 10 \\ L or l optional for primitive assignment
Long v2 = 10L \\ mandatory for autoboxing
Long v3 = new Long(10) \\ Optional