double占几个字节「精华」

用C语言测试自己编译器所占字节的大小,代码实现如下:

#include<stdio.h>

#include<climits>

#include<float.h>

int main()

{

int* p;

printf("char = %d\n", sizeof(char));

printf("signed char = %d\n", sizeof(signed char));

printf("unsigned char = %d\n", sizeof(unsigned char));

printf("short = %d\n", sizeof(short));

printf("signed short = %d\n", sizeof(signed short));

printf("unsigned short = %d\n", sizeof(unsigned short));

printf("int = %d\n", sizeof(int));

printf("signed int = %d\n", sizeof(signed int));

printf("unsinged int = %d\n", sizeof(unsigned int));

printf("float = %d\n", sizeof(float));

printf("double = %d\n", sizeof(double));

printf("long = %d\n", sizeof(long));

printf("signed long = %d\n", sizeof(signed long));

printf("unsigned long = %d\n", sizeof(unsigned long));

printf("longlong = %d\n", sizeof(LONGLONG));

printf("p = %d\n", sizeof(p));

return 0;

}

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运行结果如下:


double占几个字节「精华」

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再来看一下每个关键字的最大值

#include<iostream>

#include<climits>

using namespace std;

int main()

{

char n_char = CHAR_MAX;

char n_schar = SCHAR_MAX;

char n_uchar = UCHAR_MAX;

short n_short = SHRT_MAX;

short n_ushort = USHRT_MAX;

int n_int = INT_MAX;

unsigned int n_uint = UINT_MAX;

float n_float = FLT_MAX;

float n_maxfloat = FLT_MANT_DIG;

float n_10float = FLT_MAX_10_EXP;

long n_long = LONG_MAX;

long n_Ulong = ULONG_MAX;

long long n_llong = LLONG_MAX;

long long n_ullong = ULLONG_MAX;

cout << "max value is :" << endl;

cout << "char is:" << n_char << endl;

cout << "usigned char is:" << n_schar << endl;

cout << "unsigned char is:" << n_uchar << endl;

cout << "int is:" << n_int << endl;

cout << "unsigned int is:" << n_uint << endl;

cout << "short is:" << n_short << endl;

cout << "unsigned short is:" << n_ushort << endl;

cout << "folat is :" << n_float << endl;

cout << "numbers of float is:" << n_maxfloat << endl;

cout << "float 10_exp is:" << n_10float << endl;

cout << "long is:" << n_long << endl;

cout << "unsigned long is:" << n_Ulong << endl;

cout << "long long is:" << n_llong << endl;

cout << "unsigned long long is:" << n_ullong << endl;

return 0;

}

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运行结果:


double占几个字节「精华」

文章插图

因为char没有最大值,所以这里没有输出结果!

每个关键字的最小值

#include<iostream>

#include<climits>

using namespace std;

int main()

{

short n_short = SHRT_MIN;

int n_int = INT_MIN;

float n_float = FLT_MIN;

float n_10float = FLT_MIN_10_EXP;

long n_long = LONG_MIN;

long long n_llong = LLONG_MIN;

cout << "min value is :" << endl;

cout << "int is:" << n_int << endl;

cout << "short is:" << n_short << endl;

cout << "folat is :" << n_float << endl;

cout << "float 10_exp is:" << n_10float << endl;

cout << "long is:" << n_long << endl;

cout << "long long is:" << n_llong << endl;

return 0;

}

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运行结果:


double占几个字节「精华」

文章插图

有关每一个字节的取值范围如下: 1、char:表示字符型数据,占1个字节(8个二进制位),包含256个不同的整数 。有符号的范围: -128 ~ 127 。每个整数都对应一个字符 。整数和字符的对应关系由ASCII码表规定 。无符号的范围:0 ~ 255 。1234

2、short:表示短整型数据,一般占2个字节(16个二进制位) 。

有符号的范围:-32768 ~ 32767 。

无符号的范围0到65535 。

1234

3、int:表示基本整型数据,一般占4个字节(32个二进制位) 。

有符号的范围:-2147483648 ~ 2147483647 。

无符号的范围:0 ~ 4294967295 。

1234

4、long:表示长整型数据,一般占4个字节(32个二进制位) 。

有符号的范围:-2147483648 ~ 2147483647 。

无符号的范围:0 ~ 4294967295 。

1234

5、float:表示单精度浮点型数据,一般占4个字节(32个二进制位,1bit(符号位) 8bits(指数位) 23bits(尾数位)) 。

范围:-3.40E+38 ~ +3.40E+38

精度:6 ~ 7位有效数字

1234

6、double:表示双精度浮点型数据,一般占8个字节(64个二进制位,1bit(符号位) 11bits(指数位) 52bits(尾数位)) 。

范围:-1.79E+308 ~ +1.79E+308

精度:15 ~ 16位有效数字

1234

7、unsigned:表示无符号数据 。

【double占几个字节「精华」】8、signed:表示有符号数据,默认不用写 。

另外,我将不同位平台下关键字所占的字节的链接贴在下面: https://blog.csdn.net/cherrydreamsover/article/details/81022994

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