3. Introduction to c++: Basic Programming for beginners: Variables and Data Types in c++ :: Videos
Description:
This is the third video in the series of videos for basic programming skill in C++.
This video basically introduces what are the variables and variable identifiers in C++, how are they used and why are they important and also how to use them to make a program more useful.
Key terms:
- Variable: Portion of memory to store and determine a certain value.
- Valid identifier: sequence of letters, numbers and underscore, and cannot start with number. Can start with underscore(_) but not recommended.
- Reserved keywords: That are there already for compiler to use and we declaring them will just try to initialize again causing error.
- List of reserved keywords:
asm, auto, bool, break, case, catch, char, class, const,
const_cast, continue, default, delete, do, double,
dynamic_cast, else, enum, explicit, export, extern,
false, float, for, friend, goto, if, inline, int, long,
mutable, namespace, new, operator, private, protected,
public, register, reinterpret_cast, return, short,
signed, sizeof, static, static_cast, struct, switch,
template, this, throw, true, try, typedef, typeid,
typename, union, unsigned, using, virtual, void,
volatile, wchar_t, while
- Operator words that may be reserved:
and, and_eq, bitand, bitor, compl, not, not_eq, or, or_eq, xor, xor_eq
- List of fundamental data type:
Type |
size |
Range |
char |
1 byte |
signed: -128 to 127
unsigned: 0 to 255 |
short int
(short) |
2 bytes |
signed: -32768 to 32767
unsigned: 0 to 65535 |
int |
4 bytes |
signed: -2147483648 to 2147483647
unsigned: 0 to 4294967295 |
long int
(long) |
4 bytes |
signed: -2147483648 to 2147483647
unsigned: 0 to 4294967295 |
bool |
1 byte |
true or false |
float |
4 bytes |
+/- 3.4e +/- 38 (~7 digits) |
double |
8 bytes |
+/- 1.7e +/- 308 (~15 digits) |
long double |
8 bytes |
+/- 1.7e +/- 308 (~15 digits) |
wchar_t |
2/4 bytes |
1 wide character |
- Variables can be initialized basically in two ways:
- int a = 10; or
- int a (10);
- string variable types can store bunch of characters.
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