c++ integer->std::string conversion. Simple function?
Now in c++11 we have #include <string> string s = std::to_string(123); Link to reference: http://en.cppreference.com/w/cpp/string/basic_string/to_string
integer
Why use !! when converting int to bool?
The problems with the “!!” idiom are that it’s terse, hard to see, easy to mistake for a typo, easy to drop one of the “!’s”, and so forth. I put it in the “look how cute we can be with C/C++” category. Just write bool isNonZero = (integerValue != 0); … be clear.
PHP number: decimal point visible only if needed
floatval or simply casting to float php > echo floatval(7.00); 7 php > echo floatval(2.30); 2.3 php > echo floatval(1.25); 1.25 php > echo floatval(1.125); 1.125 php > echo (float) 7.00; 7 php > echo (float) 2.30; 2.3 php > echo (float) 1.25; 1.25 php > echo (float) 1.125; 1.125
Convert integer to hex and hex to integer
Convert INT to hex: SELECT CONVERT(VARBINARY(8), 16777215) Convert hex to INT: SELECT CONVERT(INT, 0xFFFFFF) Update 2015-03-16 The above example has the limitation that it only works when the HEX value is given as an integer literal. For completeness, if the value to convert is a hexadecimal string (such as found in a varchar column) use: … Read more
In C# integer arithmetic, does a/b/c always equal a/(b*c)?
I liked this question so much I made it the subject of my blog on June 4th, 2013. Thanks for the great question! Large cases are easy to come by. For example: a = 1073741823; b = 134217727; c = 134217727; because b * c overflows to a negative number. I would add to that … Read more
Why can’t I inherit from int in C++?
Neil’s comment is pretty accurate. Bjarne mentioned considering and rejecting this exact possibility1: The initializer syntax used to be illegal for built-in types. To allow it, I introduced the notion that built-in types have constructors and destructors. For example: int a(1); // pre-2.1 error, now initializes a to 1 I considered extending this notion to … Read more
Is there a way to get the largest integer one can use in Python? [duplicate]
Python has arbitrary precision integers so there is no true fixed maximum. You’re only limited by available memory. In Python 2, there are two types, int and long. ints use a C type, while longs are arbitrary precision. You can use sys.maxint to find the maximum int. But ints are automatically promoted to long, so … Read more
How can I pass an Integer class correctly by reference?
There are two problems: Integer is pass by value, not by reference. Changing the reference inside a method won’t be reflected into the passed-in reference in the calling method. Integer is immutable. There’s no such method like Integer#set(i). You could otherwise just make use of it. To get it to work, you need to reassign … Read more
Populating a list of integers in .NET
If you’re using .Net 3.5, Enumerable.Range is what you need. Generates a sequence of integral numbers within a specified range.
Why Use Integer Instead of Long?
Integer variables are stored as 16-bit (2-byte) numbers Office VBA Reference Long (long integer) variables are stored as signed 32-bit (4-byte) numbers Office VBA Reference So, the benefit is in reduced memory space. An Integer takes up half the memory that a Long does. Now, we are talking about 2 bytes, so it’s not going … Read more