C语言之1ULL/1UL/1L区别(五十五)

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <limits.h>
#include <iostream>
using namespace std;

#define I_MAX (1<<31) -1
#define I_MIN -(1<<31)

#define L_MAX (1ULL<<63) -1
#define L_MIN -(1ULL<<63)

//1ULL、1UL、1L：如果不指定的话就是默认的int类型，所以int类型的范围(1<<31 -1)较小
#define TEST_L_MAX (1<<63) -1
#define TEST_L_MIN -(1<<63)

int main(){
	char *str = "23344232432342";
	long long ret = 0;
	printf("I_MAX = %d\n",I_MAX);
	printf("I_MIN = %d\n",I_MIN);

	//ok
	printf("L_MAX = %lld\n",L_MAX);
	printf("L_MIN = %lld\n",L_MIN);

	//error 
	printf("TEST_L_MAX = %lld\n",TEST_L_MAX);
	printf("TEST_L_MIN = %lld\n",TEST_L_MIN);


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

	cout << endl;
	printf("INT_MAX = %d\n",INT_MAX);
	printf("INT_MIN = %d\n",INT_MIN);
	
	printf("LONG_MAX = %ld\n",LONG_MAX);
	printf("LONG_MIN = %ld\n",LONG_MIN);

	printf("LLONG_MAX = %ld\n",LLONG_MAX);
	printf("LLONG_MIN = %ld\n",LLONG_MIN);
	
	
	while(*str >= '0' && *str <= '9'){
		ret = ret*10 + (*str - '0');
		str++;
	}	
	printf("ret = %ld\n",ret);
}

打印：

I_MAX = 2147483647
I_MIN = -2147483648
L_MAX = 9223372036854775807
L_MIN = -9223372036854775808
TEST_L_MAX = 4294967295
TEST_L_MIN = 0
sizeof(unsigned long long) = 8
sizeof(unsigned long) = 8
sizeof(long) = 8

INT_MAX = 2147483647
INT_MIN = -2147483648
LONG_MAX = 9223372036854775807
LONG_MIN = -9223372036854775808
LLONG_MAX = 9223372036854775807
LLONG_MIN = -9223372036854775808
ret = 23344232432342

注意：如果没有ULL/UL/L后缀，则系统默认为 int类型.

1ULL:表示1是unsigned long long 类型(64位系统占8byte，64位)

1UL:表示1是unsigned long 类型(64位系统占8byte，64位)

1L:表示1是long 类型(64位系统占8byte，64位)