32-bit unsigned inetegers.

[joecaveman]

I need to have a variable store the number: 4294967295.

The line of code:

long int unsigned checksum = 4294967295;

Generates the warning:
[Warning] this decimal constant is unsigned only in ISO C90

Which - in my infinite ignorance - leads me to believe I must find a different compiler. How can I solve this problem?

[Ancient Dragon]

you have the data type scrambled (when declaring long keyword int is optional and rarly used with long) There is no guarentee that long is 32 bits. could be 64 bits on a 64-bit computer.

unsigned long checksum = 42...

[Rashakil Fol]

Use 4294967295u, with the u suffix to indicate unsignedness.

[Ancient Dragon]

Use 4294967295u, with the u suffix to indicate unsignedness.

you don't really need that -- the compiler will figure it out from the integer's data type. But I suppose some compilers might complain if the 'u' is not present.

[OnionKnight]

Also in cases like these it would be prettier and easier to understand if you used hex instead; 0xFFFFFFFF

[dwks]

I like

(unsigned)-1

or an equivalent.

you have the data type scrambled (when declaring long keyword int is optional and rarly used with long)

The order of keywords doesn't matter. const unsigned long int is exactly the same as unsigned long const int.

There is no guarentee that long is 32 bits. could be 64 bits on a 64-bit computer.

That's why you should use (unsigned)-1 or ULONG_MAX (in <limits.h>).