Credits to http://moeffju.net/blog/using-bigint-columns-in-rails-migrations class CreateDemo < ActiveRecord::Migration def self.up create_table :demo, :id => false do |t| t.integer :id, :limit => 8 end end end See the option :id => false which disables the automatic creation of the id field The t.integer :id, :limit => 8 line will produce a 64 bit integer field
The language guarantees that int is at least 16 bits, long is at least 32 bits, and long can represent at least all the values that int can represent. If you assign a long value to an int object, it will be implicitly converted. There’s no need for an explicit cast; it would merely specify … Read more
Note that there is a difference between a cast to long and a cast to Long. If you cast to long (a primitive value) then it should be automatically boxed to a Long (the reference type that wraps it). You could alternatively use new to create an instance of Long, initializing it with the int … Read more
%lld is the standard C99 way, but that doesn’t work on the compiler that I’m using (mingw32-gcc v4.6.0). The way to do it on this compiler is: %I64d So try this: if(e%n==0)printf(“%15I64d -> %1.16I64d\n”,e, 4*pi); and scanf(“%I64d”, &n); The only way I know of for doing this in a completely portable way is to use … Read more
long may be a 64-bit type, but 1 is still an int. You need to make 1 a long int using the L suffix: unsigned long x = 1UL << 32; (You should also make it unsigned using the U suffix as I’ve shown, to avoid the issues of left shifting a signed integer. There’s … Read more
JavaScript has a Number type which is a 64 bit floating point number*. If you’re looking to convert a string to a number, use either parseInt or parseFloat. If using parseInt, I’d recommend always passing the radix too. use the Unary + operator e.g. +”123456″ use the Number constructor e.g. var n = Number(“12343”) *there … Read more
(It is probably a bit late for the OP, but it might still be useful for others) Unfortunately Java does not support arrays with more than 231−1 elements. The maximum consumption is 2 GiB of space for a byte[] array, or 16 GiB of space for a long[] array. While it is probably not applicable … Read more
If you need larger than 32-bits you could consider using 64-bit integers (long long), or use or write an arbitrary precision math library, e.g. GNU MP.
Replace #define INT32_MIN (-2147483648L) with #define INT32_MIN (-2147483647 – 1) -2147483648 is interpreted by the compiler to be the negation of 2147483648, which causes overflow on an int. So you should write (-2147483647 – 1) instead. This is all C89 standard though. See Steve Jessop’s answer for C99. Also long is typically 32 bits on … Read more
a) Can you explain to me the difference between int64_t and long (long int)? In my understanding, both are 64 bit integers. Is there any reason to choose one over the other? The former is a signed integer type with exactly 64 bits. The latter is a signed integer type with at least 32 bits. … Read more