◎基本概念
關於float、double最大值最小值以及精準度,比較複雜不在這篇介紹,可以參考
C++ - Floating-Point Precision,float,double (C++軟體開發 - 浮點數精度 概念與實例)
◎簡單實例
Type
|
Byte
|
Range
|
char
|
1
|
-128~127 / 0~255
|
bool
|
1
|
0~1
|
int
|
4
|
-2147483648 ~ 2147483647
|
Short int
|
2
|
-32768~32767
|
Long int
|
8
|
-9223372036854775808 ~ 9223372036854775807
|
float
|
4
|
(~7 digits)
|
double
|
8
|
(~15 digits)
|
long double
|
8
|
(~15 digits)
|
Wchar_t
|
2 / 4
|
關於float、double最大值最小值以及精準度,比較複雜不在這篇介紹,可以參考
C++ - Floating-Point Precision,float,double (C++軟體開發 - 浮點數精度 概念與實例)
◎簡單實例
依照complier還有電腦環境,可以與上面表格不同,可以用利用下列程式碼確認大小。
#include "stdafx.h" #include <iostream> #include <limits> using namespace std; int main() { cout << "Size of char : " << sizeof(char) << endl; cout << "min:" << (numeric_limits<char>::min)() << " "; cout << "MAX:" << (numeric_limits<char>::max)() << endl; cout << "Size of bool : " << sizeof(bool) << endl; cout << "min:" << (numeric_limits<bool>::min)() << " "; cout << "MAX:" << (numeric_limits<bool>::max)() << endl; cout << "Size of int : " << sizeof(int) << endl; cout << "min:" << (numeric_limits<int>::min)() << " "; cout << "MAX:" << (numeric_limits<int>::max)() << endl; cout << "Size of short int : " << sizeof(short int) << endl; cout << "min:" << (numeric_limits<short int>::min)() << " "; cout << "MAX:" << (numeric_limits<short int>::max)() << endl; cout << "Size of long int : " << sizeof(long int) << endl; cout << "min:" << (numeric_limits<long int>::min)() << " "; cout << "MAX:" << (numeric_limits<long int>::max)() << endl; cout << "Size of float : " << sizeof(float) << endl; cout << "min:" << (numeric_limits<float>::min)() << " "; cout << "MAX:" << (numeric_limits<float>::max)() << endl; cout << "Size of double : " << sizeof(double) << endl; cout << "min:" << (numeric_limits<double>::min)() << " "; cout << "MAX:" << (numeric_limits<double>::max)() << endl; cout << "Size of long double : " << sizeof(long double) << endl; cout << "min:" << (numeric_limits<long double>::min)() << " "; cout << "MAX:" << (numeric_limits <long double > ::max)() << endl; cout << "Size of wchar_t : " << sizeof(wchar_t) << endl; cout << "min:" << (numeric_limits<wchar_t>::min)() << " "; cout << "MAX:" << (numeric_limits <wchar_t > ::max)() << endl; return 0; }
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