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| int a = 2, b; b = a+3; | Int a=2; // int INT a=2; |
| int a = 2, b; b = A + 3; // | |
| int a = 2; b = a + 3; // b |
.
0 2n-1, n- .
-2n-1...+2n-1-1. (0 , 1 ).
:
| unsigned char 0...255 | char -128...127 | |
| unsigned short 0...65535 | short -32768...32767 | |
| unsigned int | int | |
| unsigned long int | long int |
. . ( 0) . . , 12345,678
12345,678 = 1,2345678104
0,009876
0,009876 = 9,87610-3
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| double | 62...52 | 51...0 | |||
| long double | 78...64 | 62...0 |
, float double . , . , float :
: -178,125 32- ( float).
:
17810 = 101100102.
0,12510 = 0,0012. 178,12510 = 10110010,0012=1,01100100012111
( 7 ).
:
0111111+00000111 = 10000110.
, -178,125
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int n; // n
double a; // a
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| (0 7), 0. : 00, 071, -052, -03. | |
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. binary.h, .
|
|
|
:
#include <stdio.h>
#include "binary.h"
int main()
{
unsigned char p = b10001001 | b00001010; // p=b10001011=139
printf("p = %dd = %xh", p, p);
getchar(); getchar();
return 0;
}
(char, int, long int).
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double. , , : F ( f) float , L ( l) long double .
:
3.14159F float, 4 ;
3.14L long double, 10 .
, : 'z'. , . '\' ( ).
| 0x00 | '\0' | -, NULL |
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| 0x08 | '\b' | 1 (Backspace) |
| 0x09 | '\t' | (Tab) |
| 0x0A | '\n' | (Enter) |
| 0x0B | '\v' | ( ) |
| 0x0C | '\f' | |
| 0x0D | '\r' |
, "Enter" - (0x0A) (0x0D).
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|
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char a='a';
:
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c .
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;
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:
int a = 4; // a 4
int b;
b = a + 2; // b 6,
//
.
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float a = 241.5;
// a
int b = (int)a % 2; // b = 1
:
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| int a=2; int b=3; int c; c = a*++b; // c=8, b=4 | int a=2; int b=3; int d; d = a*b++; // d=6, b=3, b=4 |
:
*= ; // = *
/= ; // = /
+= ; // = +
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%= ; // = %
:
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1 ;
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:
unsigned char a = 14; // a = 0000 1110
unsigned char b = 9; // b = 0000 1001
unsigned char c, d, e, f;
c = a & b; // c = 8 = 0000 1000
d = a | b; // d = 15 = 0000 1111
e = ~a; // e = 241 = 1111 0001
f = a ^ b; // f = 7 = 0000 0111
. . , ,
| 0x01 | |
| 0x02 | |
| 0x04 | |
| 0x08 | |
| 0x10 | |
| 0x20 | |
| 0x40 | |
| 0x80 |
1 , :
unsigned char a = 3;
a = a | 0x04; // a = 7, 2
0 , :
unsigned char a = 3;
a = a & (~0x02); // a = 1, 1
:
&= ; // = &
|= ; // = |
^= ; // = ^
:
>> - ;
<< - .
:
= ;
:
unsigned char a=6; // a = 0000 0110
unsigned char b;
b = a >> 1; // b = 0000 0110 >> 1 = 0000 0011 = 3
>> 1 2.
<< 1 2.
|
|
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. stdio.h.
printf() -
scanf() - .
printf() . . ,
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printf("", 1, 2,..., n);
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%lu unsigned long int;
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%f ( float);
%lf ( double);
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%c ;
%s .
int a=5;
float x = 2.78;
printf("\n a=%d", a);
printf("\n x=%f", x);
a=5
x=2.780000
, .
float y=1.2345;
printf("\n y=%10.5f\n", y);
y= 1.23450
10 ; 5 . 10, . .
scanf() , , . .
scanf()
scanf ("C ", 1, 2,...);
printf(). '&':
= &
.
#include <stdio.h>
#include <stdlib.h>
int main()
{
float y;
system("chcp 1251");
system("cls");
printf(" y: ");
scanf("%f",&y); // y
printf(" y=%f",y);
getchar(); getchar();
return 0;
}
, . .
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if
if .
| if(){ ; } | if(){ 1; } else { 2; } |
| 
|
, , , .
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. , , .
#include <stdio.h>
int main() {
int k;
printf("k= ");
scanf("%d",&k);
if(k >= 5) {
printf("%d >= 5", k);
} else {
printf("%d < 5", k);
}
getchar(); getchar();
return 0;
}
if .
:
#include <stdio.h>
#include <stdlib.h>
int main() {
int key;
system("chcp 1251");
system("cls");
printf(" , 1 2: ");
scanf("%d",&key);
if (key == 1)
printf("\n ");
else if (key == 2)
printf("\n ");
else
printf("\n ");
getchar(); getchar();
return 0;
}
if else if. else if, :
if (key!= 1) {
if (key == 2)
printf("\n ");
} else
printf("\n ");
3 , .
? 1: 2;
, 1, - 2.
, , . .
#include <stdio.h>
#include <stdlib.h>
int main() {
int key;
system("chcp 1251");
system("cls");
printf(" , 1 2: ");
scanf("%d",&key);
key == 1? printf("\n "):
(key==2? printf("\n "):
printf("\n "));
getchar(); getchar();
}
switch ( )
if . , if. switch.
switch ( ) {
case 1: 1;
break;
case 2: 2;
break;
...
case n: n;
break;
default: ;
break;
}
switch :
switch;
() case, , , ;
case;
, default.
default , .
break; switch . break , default.
case ( ).
:
. switch.
#include <stdio.h>
#include <stdlib.h>
int main() {
int day;
system("chcp 1251");
system("cls");
printf(" : ");
scanf("%d", &day);
switch (day) {
case 1:
printf("");
break;
case 2:
printf("");
break;
case 3:
printf("");
break;
case 4:
printf("");
break;
case 5:
printf("");
break;
case 6:
printf("");
break;
case 7:
printf("");
break;
default:
printf(" ");
break;
}
getchar(); getchar();
return 0;
}
, .
, .
, . . , , .
:
while - ;
do...while - ;
for - ( ).
while
while() {
;
}
( ), , , . , , , ( ). , , .
int k=5;
int i=1;
int sum=0;
while(i <=k)
{
sum = sum + i;
i++;
}
while, , , ( ). ( ),
while(1) {
;
}
while , , .
int k=5;
int n=10;
while(k>n)
{
printf(" k=%d n=%d \n", k, n);
k = k + 2;
}
