ตัวแปร

คำสงวน

alignas, alignof, and, and_eq, asm,
auto, bitand, bitor, bool, break,
case, catch, char, char16_t, char32_t,
class, compl, const, constexpr, const_cast,
continue, decltype, default, delete, do,
double, dynamic_cast, else, enum, explicit,
export, extern, false, float, for, friend,
goto, if, inline, int, long, mutable,
namespace, new, noexcept, not, not_eq,
nullptr, operator, or, or_eq, private,
protected, public, register, reinterpret_cast,
return, short, signed, sizeof, static,
static_assert, static_cast, struct, switch,
template, this, thread_local, throw, true,
try, typedef, typeid, typename, union, unsigned,
using, virtual, void, volatile, wchar_t, while,
xor, xor_eq

ชนิดข้อมูลพื้นฐาน

Group	Type	Remark
Characters	char
	char16_t
	char32_t
	wchar_t
Integers (signed)	signed char
	signed short int
	signed int
	signed long int
	signed long long int
Integers (unsigned)	unsigned char
	unsigned short int
	unsigned int
	unsigned long int
	unsigned long long int
Floating-point	float
	double
	long double
Boolean	bool
Void	void
Null pointer	decltype(nullptr)

ช่วงค่าข้อมูล

Type	Macro	Min Value	Max Value	Macro	Remark
char	CHAR_MIN	-128	127	CHAR_MAX
short char	SCHAR_MIN	-128	127	SCHAR_MAX
unsigned char		0	256	UCHAR_MAX
short	SHRT_MIN	-32,768	32,767	SHRT_MAX
unsigned short int		0	65,535	USHRT_MAX
int	INT_MIN	-2,147,483,648	2,147,483,647	INT_MAX
unsigned int		0	4,294,967,295	UINT_MAX
long	LONG_MIN	-9,223,372,036,854,775,807	9,223,372,036,854,775,807	LONG_MAX
unsigned long	ULONG_MIN	0	18,446,744,073,709,551,615	ULONG_MAX
long long	LLONG_MIN	-9,223,372,036,854,775,807	9,223,372,036,854,775,807	LLONG_MAX
unsigned long long		0	18,446,744,073,709,551,615	ULLONG_MAX
float	FLT_MIN	1.17549E-38	3.40282E+38	FLT_MAX
double	DBL_MIN	2.22507E-308	1.79769E+308	DBL_MAX

ตัวแปร

int a;
long long b;
float c;
double x, y, z;

การกำหนดค่า

int x = 0;
long y (0);
double x {0.0};

ประเภทข้อมูลอัตโนมัติ

int x = 0;
auto y = x;      // int y;
decltype(x) z;   // int z;

ข้อความ

การกำหนดค่า

string name = "Paul Phoenix";
string paul ("Paul Phoenix");
string p {"Paul Phoenix"};

ตัวอย่างโปรแกรม

#include <bits/stdc++.h>

using namespace std;

int main() {
  string name = "Paul Phoenix";

  cout << name << endl;

 return 0;
}