, , . .
, . , , : (.), (,), (:), (;) . , , .
. . ASCII, ASCII-.
. . , : - 710, - 810, - 910, - 1010, - 1310 .. 0 - 31, 127.
, 28 = 256. , , 256 :
_____ - .
, , ..
, (, , .). :
- (,...,z, ,...,Z) (_).
- , (0,...,9). .
- (,...,z), , (,...,Z). , : name, NaMe, NAME ..
- , (, , ..) . , ANSI C 32 ( ++ ). 5, count counter , .
2) :
, .
-. {}.
|
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, main().
" " -;. .
,
( ). .
/* - ;
*/ - .
, , .
:
int a; /*
*/
.
, //. , // :
float b; //
, , main(). main() , .
(), . main() , .
-:
int main()
void main().
. . . void main() - , , main() .
int main() , , . , , .
return 0; //
.
. , , , , .
: "Hello, world!".
#include <stdio.h> // -
int main() //
{
printf("Hello, world!"); //
getchar(); //
return 0;
}
:
Hello world
.
#include <stdio.h>
int main()
{
printf(", !");
getchar();
|
|
return 0;
}
:
, !
, Microsoft Visual Studio . , , (1251). system("chcp 1251") . system() <stdlib.h>.
:
#include <stdio.h>
#include <stdlib.h>
int main()
{
system("chcp 1251"); // 1251
system("cls"); //
printf(", !"); //
getchar();
return 0;
}
:
, !
3)
ASCII () 0 127 . , () , ('!', '%', '~' ..). , , - (, , .). ASCII (, ) 128 255. '0' '9' 48 57. , "" . , '0' 48, '5', 53, 53 48, 5. . () 65 (A) 90 (Z), () 97 122.
, .. . . , 'a' , , ? : '\n'. , . ( ) , : '\n' ; '\t' ( ); '\r' ( ); '\b' . , , , , , . . , .. - . , , , . : '\\' ; '\'' ; '\"' ( '"'); '\0' , 0 ASCII.
4):
. . :
- ;
- ;
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- ;
- ,
, :
- ( );
- ;
- , .
, : , , , , , ( ).
. , , . , , .
: , , , , .
: . -, , NAME1, name 1, Name 1, name_1
: . .1.1
1.1
Eng | Eng | |||||
har | Asm | |||||
Class | Break | |||||
Double | Case | |||||
Enum | Continue | |||||
Float | Default | |||||
. 1.1 | ||||||
Int | Delete | |||||
Long | Do | |||||
Short | Else | |||||
Struct | For | |||||
Union | Go to | () | ||||
Unsigned | If | |||||
Void | New | |||||
Return | Switch | |||||
Extern | Inline | |||||
Register | Const | |||||
Overload | Typedef | |||||
Auto | While | |||||
Static | Public | |||||
: , , , .
. - , 0, . 8 9 . 0X 0x . A F(f), 10 15.
: 0x53=83; 0xF=15; 0xA = 10.
, , (long), (int).
: , , L (l), .
: 12l - ,
0123L - ,
0xaaaal - .
. 1.2.
. , 0xAB01 0x53, , [1].
1.2
- | - | -- | ||
0x0 | ||||
0x1 | ||||
0x2 | ||||
0x3 | ||||
0x4 | ||||
0x5 | ||||
0x6 | ||||
0x7 | ||||
0x8 | ||||
0x9 | ||||
A | 0xA | |||
B | 0xB | |||
C | 0xC | |||
D | 0xD | |||
E | 0xE | |||
F | 0xF |
|
|
A B 0 1
1010 1011 0000 0001 > 1010101100000001=
1 * 215 + 0 * 214 + 1 * 213 + 0 * 212 + 1 * 211 + 0 * 210 + 1 * 29+ 1 * 28 + 1 * 20 = 43777;
0x53 = 01010011 = 0 * 27 + 1 * 26 + 0 * 25 + 1 * 24 + 0 * 23 + 0 * 22 + 1* 21 + 1 * 20 = 83;
, (, x). (). char. , \ .1.3
1.3
\n | |
\t | |
\v | |
\b | |
\v | |
. 1.3 | |
\f | |
\\ | |
\ | |
0ddd | \ddd |
0xddd | \xddd |
\0 |
\ddd , 1, 2, 3 - , . \xddd , 1, 2, 3 .
( ) .
: 345. = 345
3.14159
2.15 = 210000
.1233 = 123
4037-5 =.04037
. , . char, static. . , , . () \O , . \. , , .
:
A
\*\
. , , , . , . , .
. , .
. : , , .
- , , . , , .
, . , , .
- , - .
2: C++. .
1) C++:
, .
, . , display, , PC. , , , . main() display. .
//
#include <iostream.h>
enum disp_type {mono, cga, ega, vga};
class display {
int colors; // enum
disp_type dt; //
public:
void set_colors(int num) {colors = num; }
int get_colors() {return colors;}
void set_type (enum disp_type t) {dt = t; }
enum disp_type get_type() {return dt; }
};
char names [4 ] [5] = {
"mono",
"cga",
"ega",
"vga"
};
int main()
{
display monitors [3];
register int i;
monitors[0].set_type(mono);
monitors[0].set_colors(1);
monitors[1].set_type(cga);
monitors [1].set_colors(4);
monitors[2].set_type(ega);
monitors [2].set_colors(16);
for (1=0; i<3; i++) {
cout << names[monitors[i].get_type()] << " ";
cout << "has " << monitors[i].get_colors();
cout << " colors" << "\n";
}
return 0;
}
|
|
:
mono has 1 colors
cga has 4 colors
ega has 16 colors
, , names . , , 0, 1 . . get_type() names, .
, .
2
1: C.
" " " ". - , , , - . , , - . , :
- char - ;
- int - ;
- float - ;
- double - ;
- void - .
, , .
. :
.
.
, .
, .
,
,
.
()
- .
- , .
- ( ), .
- , - , .
, , . . ().
, 32 , a - z, A - Z, 0 - 9 (_). .
, , 32 , 8 . , . , , .
.
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
, , 1. (, 0), 0.
, , .
4 .
- , (0 , 1 - ).
- 2, . 2 , , 2 ,
N-1
n - , .
- , 1, 1.
- , .
:
- | - | ||||
float | 30...23 | 22...0 | |||
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
. . char.
: - , .
. .
int n; // n
double a; // a
2: C++. .
++ . .
:
& = 2;
2 .
!
int a,b;
int &alt=a; // alt ( a)
alt = b; // a=b;
alt++; // a++;
int *ptr = &a;
:
*ptr == alt; // ,
ptr == &alt; // ,
, , *.
, .
:
const char &new_line='\n';
temp :
char temp = '\n';
const char &new_line = temp;
++ . :
, ;
, .
, :
-, ,
-, , .
. , :
void swap (int *a, int *b) { int temp = *a; *a = *b; *b = temp; } | void swap (int &a, int &b) { int temp = a; a = b; b = temp; } |
: int x = 10; int y = 5; swap(&x, &y); | : int x = 10; int y = 5; swap(x, y); |
, :
, , . , , , const. , const .
, ++ , .
void swap (int &, int &);
int main() {
int x=10;
unsigned int y;
y=5;
swap(x, y);
...
}
:
int temp = (int)y;
int &t = temp;
swap(x, t);
swap() x temp. temp , y .
++ , . . ,
, return; .
, return . ( , ).
.
3:
1: / C.
,
. -.
. stdio.h.
printf() -
scanf() - .
printf() . . ,
.
printf():
printf("", 1, 2,..., n);
:
;
, ;
, .
.
, . '\' .
:
'\n' ;
'\t' ;
'\v' ;
'\b' ;
'\r' ;
'\a' .
, , . '%' :
%d int ;
%u unsigned int;
%x int ;
%o int ;
%hd short ;
%hu unsigned short;
%hx short ;
%ld long int ;
%lu unsigned long int;
%lx long int ;
%f ( float);
%lf ( double);
%e ( float );
%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;
}
:
2: C++. this
1) C++
. ++ , . ++.
(.). , (>). .
, . P_example ob, P_example. , ob :
//
#include <iostream.h>
class P_example {
int num;
public:
void set_num(int val) {num = val; }
void show_num();
};
void P_example::show_num()
{
cout << num << " \n";
}
int main()
{
P_example ob, *p; //
ob.set_num(1); // ob
ob.show_num();
= &ob; // ob
p->show_num(); // ob
return 0;
}
, ob & , .
, . . , ob P_example. , :
//
#include <iostream.h>
class P_example {
int num;
public:
void set_num(int val) {num = val;}
void show_num();
};
void P_example::show_num()
{
cout << num << "\n";
}
int main()
{
P_example ob[2], *p;
ob[0].set_num(10); //
ob[1].set_num(20);
p = &ob[0]; //
p->show_num(); // ob[0]
++; //
p->show_num(); // ob[1]
--; //
p->show_num(); // b [0]
return 0;
}
10, 20, 10.
2) this
, -, , . , this. this -. (- this.) , :
b.f();
f() this, ob.
, - . , :
class cl {
int i;
//...
};
- i 10, :
i = 10;
:
this->i = 10;
, , this, :
#include <iostream.h>
class cl {
int i;
public:
void load_i(int val) { this->i = val; } // , i = val
int get_i() { return this->i; } // , return i
};
int main ()
{
cl o;
o.load_i(100);
cout << o.get_i();
return 0;
}
100.
4
1: C.
" " " ". - , , , - . , , - . , :
- char - ;
- int - ;
- float - ;
- double - ;
- void - .
, , .
. :
.
.
, .
, .
,
,
.
()
- .
- , .
- ( ), .
- , - , .
, , . . ().
, 32 , a - z, A - Z, 0 - 9 (_). .
, , 32 , 8 . , . , , .
.
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
, , 1. (, 0), 0.
, , .
4 .
- , (0 , 1 - ).
- 2, . 2 , , 2 ,
N-1
n - , .
- , 1, 1.
- , .
:
- | - | ||||
float | 30...23 | 22...0 | |||
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
. . char.
: - , .
. .
int n; // n
double a; // a
2: C++. .
++ . .
:
& = 2;
2 .