integer
How to byte-swap a 32-bit integer in python?
One method is to use the struct module: def swap32(i): return struct.unpack(“<I”, struct.pack(“>I”, i))[0] First you pack your integer into a binary format using one endianness, then you unpack it using the other (it doesn’t even matter which combination you use, since all you want to do is swap endianness).
C++ – how to find the length of an integer
Not necessarily the most efficient, but one of the shortest and most readable using C++: std::to_string(num).length()
One memory location in a computer stores how much data?
Most commonly, modern systems are what you call “byte-accessible”. This means: One memory location stores 1 byte (8 bits). The basic storage unit for memory is 1 byte. If you need to store 4 bytes, and place the first byte at 0001, the last byte will be at 0004. That’s one byte at each of … Read more
Why is this function call ambiguous?
It has little to do with rank of the type defined in 4.13. 4.13 defined internal rankings used to describe integral promotions and usual arithmetic conversions. They by itself do not directly affect overload resolution. Rankings relevant to overload resolution are defined in “13.3.3.1.1 Standard conversion sequences” and then used in “13.3.3.2 Ranking implicit conversion … Read more
Extract numbers from a string using sed and regular expressions
is this ok? sed -r ‘s/.*_([0-9]*)\..*/\1/g’ with your example: kent$ echo “./pentaray_run2/Trace_220560.dat”|sed -r ‘s/.*_([0-9]*)\..*/\1/g’ 220560
How do I convert an integer to a float in JavaScript?
What you have is already a floating point number, they’re all 64-bit floating point numbers in JavaScript. To get decimal places when rendering it (as a string, for output), use .toFixed(), like this: function intToFloat(num, decPlaces) { return num.toFixed(decPlaces); } You can test it out here (though I’d rename the function, given it’s not an … Read more
Specifying 64-bit unsigned integer literals on 64-bit data models
You should use <cstdint> / <stdint.h>, if you have it. This will give you: uint64_t is an unsigned integer type which is 64 bits in size UINT64_C() is a macro for creating constants of the type uint64_t, by having the macro append the proper suffix.
How to convert Nvarchar column to INT
CONVERT takes the column name, not a string containing the column name; your current expression tries to convert the string A.my_NvarcharColumn to an integer instead of the column content. SELECT convert (int, N’A.my_NvarcharColumn’) FROM A; should instead be SELECT convert (int, A.my_NvarcharColumn) FROM A; Simple SQLfiddle here.
Check if int is between two numbers
One problem is that a ternary relational construct would introduce serious parser problems: <expr> ::= <expr> <rel-op> <expr> | … | <expr> <rel-op> <expr> <rel-op> <expr> When you try to express a grammar with those productions using a typical PGS, you’ll find that there is a shift-reduce conflict at the point of the first <rel-op>. … Read more