Apr 05, 2011 Teams. Q&A for Work. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. 14.1.4 Character Set. MySQL has a very flexible character set support as documented in Character Sets, Collations, Unicode. The list of character sets along with the names and IDs of their default collations can be queried as follows: The following table shows a few common character sets.
Variables are an extremely core concept to most object orientated programming languages. I like to visualize a variable much like a box. We can put things in the box, we can take things out of the box, and at any point we can see what is inside the box. Each box also has a name to which we can refer to it by, and in C++, each box can only hold a certain type of data.
When we create variables we call this the variable declaration, and then when we set them for the first time, we call this the initialization. To declare a variable in C++, we write the function. To declare a basic integer variable called 'age', we could write the following:
From this point we can then refer to the variable by its name, so in this case, we can just write 'age' whenever we want to refer to the variable. To initialise the variable we can write its name, followed by the equals sign, followed by the value we want to set the variable to (followed by a semicolon). The value we set it to can be a constant (a value that doesn't change), or another variable of the same type. An operator is a symbol which has a certain meaning in the programming language, in this case, the equals operator, represented by the
=
symbol, is an operator which sets whatever is on the left of the operator to whatever is on the right.The constant value we set the variable to depends on the to 5 with something like the following:
We can actually combine the variable declaration and initialization into one more-compact line, like the following:
The 'age' variable now contains the number '5', and we can refer to this '5' by writing 'age' anywhere in our program. We can also change the value of the variable at any point by using the equals operator as we did for the first initialization:
Although this seems purely for convenience at the moment (as we could just write '5', '3', or '21' in place of 'age'), trust me when I say that these become extremely useful and powerful when you start dealing with dynamic logic and user input (the latter of which we'll be covering later in this tutorial).
Just to give an example of accessing the contents of variables by using their names, we could create a new variable called 'age_two' which is set to the value of 'age', and then we can also try outputting one or both of these variables:
To be clear, all this code should be going into the basic program structure which we learnt how to create in the last tutorial. 808 massacre v3 vst free download. So we want our 'iostream' include for
cout
, cin
, and some other stuff, we want the std
namespace, and we want the majority of our code to be going in our 'main' function. So our full code to demonstrate variables so far, which you can compile and run at any point to test the functionality, is as follows:Some number variables can handle positive and negative numbers, whereas 'unsigned' number variables can only handle positive numbers, although because of this restriction, can hold larger numbers. You can write the
signed
or unsigned
keywords before the and 'short' - numbers with a decimal place in. Floats are accurate to around 6 or 7 digits and are declared using the float
type. Float constants can be defined by simply writing a number with a decimal point followed by the 'f' notation. An example of a simple float declaration and initialization to a float constant is as follows:Care must be taken, however, with float (and other decimal) operations, as rounding and precision problems to do with how the numbers are stored can trip you up (we don't have infinite memory for recurring decimals like
1/3
for example) -- I recommend reading this article for more information on this if you're interested.Will boot camp always work on mac download. In Windows on your Mac, do one of the following: Restart using Startup Manager: Restart your Mac, then immediately press and hold the Option key. Restart using Boot Camp Control Panel: Click in the right side of the taskbar, click the Boot Camp icon, then choose Restart in macOS.
Doubles
The 'double' or 'e'. Character variables are declared by using the
char
type, and character constants are defined by using single quotes (apostrophes) around the character. An example of character declaration and initialization to a character constant is as follows:Strings
The lastve talked about string variables in relation to
cout
before, and as such you should know that string constants are defined by using double quotes. String variables are declared by using the string
type, however as strings aren't actually 'primitive' types in C++ (and are instead defined by the standard library of stuff that comes bundled with C++), you are required to #include <string>
to use thist strings aren't massively useful, but this is just because we don't really know how to utilize all the functionality of different data-types yet - for example, we don't know how to perform simple mathematics on number types, or how to check the value of booleans to change the logic of the program. All will be revealed in future tutorials.The standard char variable in C++ is a scant 1 byte wide and can handle only 255 different characters. This is plenty enough for European languages but not big enough to handle symbol-based languages such as kanji.
Several standards have arisen to extend the character set to handle the demands of these languages. UTF-8 uses a mixture of 8-, 16-, and 32-bit characters to implement almost every kanji or hieroglyph you can think of but still remain compatible with simple 8-bit ASCII. UTF-16 uses a mixture of 16- and 32-bit characters to achieve an expanded character set, and UTF-32 uses 32 bits for all characters.
UTF stands for Unicode Transformation Format, from which it gets the common nickname Unicode.
The table describes the different character types supported by C++. At first, C++ tried to get by with a vaguely defined wide character type, wchar_t. This type was intended to be the wide character type native to the application program’s environment. C++ ‘11 introduced specific types for UTF-16 and UTF-32.
Dev C++ Programs
Variable | Example | What It Is | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
char | ‘c’ | ASCII or UTF-8 characters | wchar_t | L’c’ | Character in wide format | char_16t | u’c’ | UTF-16 character | char_32t | U’c’ | UTF-32 character |
Dev C++ Games
UTF-16 is the standard encoding for Windows applications. The wchar_t type refers to UTF-16 in the Code::Blocks/gcc compiler.
Dev C++ Character Setting
Any of the character types in the table can be combined into strings as well: