if...else () . . if-else if-else. switch.
Switch ( )
{
case 1:
;
case 2:
;
default:
;
}
. case 'a': , . , default. default , switch . break switch . switch , chr. .
//
#include <stdio.h>
void main(void)
{
int x, y;
char c;
printf(" 2 ");
scanf( %d %d %c, &x, &y, &c);
switch (c) {
case '+': printf("x + y = %3d\n, x+y);
break;
case '-': printf("x - y = %3d\n, x-y);
break;
case '*': printf("x * y = %3d\n, x*y);
break;
case '/': printf("x / y = %3d\n, x/y);
break;
default:
printf(" !\n);
}
}
while
.
: , , .
) :
while : while, , - , , ( , {} ). , while while ;.
while ( ) while ( ){
; ;
}
 |
while
( )
.
.
1: 2:
index = 0; index = 0;
while (index++ < 10) while (index++ < 10) {
sum = 10*index + 2; sum = 10*index + 2;
printf ("sum = % d \n", sum); printf ("sum = % d \n", sum);
}
1 . 1 ( sum=102). 2 , .
, . , .
|
|
|
, , , . .
// while
#include <stdio.h>
void main(void)
{
int guess=1;
char res;
printf(" 1 100. ");
printf("\n , );
printf(\n , .\n);
printf(" %d?\n", guess);
while((res=getchar())!= '')
if(res!='\n')
printf(" %d?\n", ++guess);
printf(", !!!");
}
) ( . , , ). 1 .
do do {
; ;
while ( ); } while ( );
. .
 |
Do while
:
1 2
do { while((ch = getchar())! = '\n')
ch = getchar(); putchar (ch);
putchar (ch);
} while(ch! = '\n')
getchar() , , . putchar , , , , .. , . : putchar(getchar()) .)
. , ( , , ).
, .
