2018/11/10
1、手動輸入內容
#include <stdio.h>
#include <cstdlib>
int main ( )
{
int n;
scanf ( "%d" , & n) ;
printf ( "%d\n" , n) ;
int a, b;
scanf ( "%d%d" , & a, & b) ;
printf ( "%d\t%d" , a, b) ;
char str1[ 10 ] ;
scanf ( "%5s" , str1) ;
printf ( "%s\n" , str1) ;
char str2[ 10 ] ;
gets ( str2) ;
printf ( "%s\n" , str2) ;
char str3[ 10 ] ;
scanf ( "%[^\n]" , str3) ;
printf ( "%s\n" , str3) ;
char str4[ 10 ] ;
fgets ( str4, sizeof ( str4) , stdin ) ;
printf ( "%s" , str4) ;
return EXIT_SUCCESS;
}
2、佔位符
#include <stdio.h>
#define PI 3.1415926
int main ( )
{
const float PI_2 = 3.14159 ;
printf ( "%s%f\n" , "Global constant:" , PI) ;
printf ( "%f\n" , PI_2) ;
int a = - 10 ;
printf ( "%u\n" , a) ;
printf ( "%d\n" , a) ;
int b = 0566 ;
printf ( "%o\n" , b) ;
int c = 0x555 ;
printf ( "%x\n" , c) ;
printf ( "%X\n" , c) ;
return 0 ;
}
3、bit爲二進制數的長度(有多少個數字就是多少位)
4、 1字節=8位(1Byte = 8bit)
5、數據類型:
short <= int <= long < long long
數據類型
佔用空間
short
2字節
int
4字節
long
windows:4字節;Linux32:4字節;Linux64:8字節
long long
8字節
#include <stdio.h>
int main ( )
{
short a = 10 ;
int b = 20 ;
long c = 30 ;
long long d = 40 ;
printf ( "%d\n" , sizeof ( a) ) ;
printf ( "%d\n" , sizeof ( b) ) ;
printf ( "%d\n" , sizeof ( c) ) ;
printf ( "%d\n" , sizeof ( d) ) ;
return 0 ;
}
6、字符型(char)
#include <stdio.h>
int main ( )
{
char ch = 'a' ;
printf ( "%c\n" , ch) ;
printf ( "%d\n" , ch) ;
printf ( "sizeof:%d\n" , sizeof ( ch) ) ;
char ch1 = 'a' ;
char ch2 = 'A' ;
printf ( "%d\n" , ch1 - ch2) ;
printf ( "%c\n" , ch1 - 32 ) ;
printf ( "%c\n" , 99 ) ;
printf ( "\a" ) ;
return 0 ;
}