-

42 C 3: 43

3

C

:

1. printf() .2. printf() .3. scanf() .4. printf() scanf() .5. getchar() .6. putchar() .7. getche() .8. getch() .9. gets() puts() .

C . stdio.h . scanf printf . . getchar putchar . gets puts . . . . printf() . . . . printf ("control string", arguments list) ;

printf ("control string", arg1, arg2,, argn) ;

. . "%" . type conversion "%" . . printf 31 . 31 printf ()

. %c

. %d

. %i

.%f

floating-point . %e

floating-point %f %e ( ) . %g

. %u

. %s

8 . %o

16 . %x

%o , %x , %u , %d ( ld). L

. %p

% . %%

( 31 .#include

main ()

{ int x =31 ;

float y =148.5 ; char z[10] = {"PayamNoor"};

printf(" %d %f %s " , x , y , z) ;

} %s ,%f , %d . .

31 148.5 PayamNoor

.

(( 32 .

#includemain ()

{

float x=2.0 , y=3 ;

printf("%f %f %f %f %d", x , y , x+y , x*y, x) ;

} .

2.0000003.0000005.0000006.000000 2

. . .(( 33 .

#include

main ()

{ double x=50.0 , y=0.25 ; printf(" %f %f %f %f\n ", x , y , x*y , x / y) ;

printf(" %e %e %e %e ", x , y , x*y , x / y) ;

}

printf %f %e . "\n" . .

50.000000 0.250000 12.500000 200.000000

5.000000e+01 2.500000e-01 1.250000e+01 2.000000e+02

x/y , x*y , y , x floating point "%e" . 6 . . . ( ) ( ). ( ) % . . . m "0" . %04d . floating point "." . %10.4f .

(( 34 .

#includemain ()

{

int x = 12345 ; float y =345.125 ; printf("3d %5d %8d\n\n", x , x , x) ; printf("%3f %10f %13f\n", y , y , y) ; printf("%3e %10e %13e\n", y , y , y) ; printf("%g %10g %13g \n", x , x , x) ;

printf("%3g %10g %13g ", x , x , x) ; } .

12345 12345 12345

345.125000 345.125000 345.125000

3.45125e+02 3.45125e+02 3.45125e+02

345.125 345.125 345.125

345.125 345.125 345.125

( ) . ( 5 ). . . blank . ( ). . f e . %g . . .

floating point . precision . "." . precision ( ) precision "." . floating point precision .

(( 35 . #include

main ()

{

float x =123.456 ; printf("%7f %7.3f %7.1f\n", x , x , x) ; printf("%12e %12.5e %12.3e", x , x , x) ;

}

.

123.456000 123.456 123.5

1.234560e+02 1.23456e+02 1.235e+02 f . . ( ) . e . 3 . ( ) .( . .

printf(" %.4f ", x) ;

flag . flag (%) . flag . flag C 32 . 32 Flag

Flag

. ._

(+ -) . flag .+

blank . .0

blank . (+) . blankspace

0 0x .#( 0- x-)

floating-point "." . g .#( e- g-, f-,)

( 36 . #include

main ()

{

int x =123 ; float y =45.0 , z = -6.7 ; printf(": %5d %7.0f %10.1e: \n", x , y , y) ; printf(": %-5d %-7.0f %-10.1e: \n", x , y , z) ; printf(": %+5d %+7.0f %+10.1e: \n", x , y , z) ; printf(": %7.0f %#7.0f %7g %#g: " , y , y , z , z) ;

}

":" .

: 123 45 -6.7+00:

: 123 45 -6.7e+00:

: +123 +45 -6.7e+00:

:+123 +45 -6.7e+00:

: 45 45. -6.7 -6.500000:

. "-" . "+" . . ( ) . "-" "+" . "-" "+" . "#" 45 "g" .

(( 37 8 10 16 . #include

main ()

{ int x = 1234 , y = 0155 , z = 0xa06b ;

printf(": %6u %6o %6x: \n", x , y , z) ;

printf(": %-6u %-6o %-6x: \n", x , y , z) ;

printf(": %#6u %#6o %#6X: \n" , x , y , z) ;

printf(": %06u %06o %06X: ", x , y , z) ;

}

":" .

: 1234 155 a06b:

:1234 155 a06b:: 1234 0155 0XA06B::001234 000155 00A06B: 10 8 16 . "-" . "#" . 8 16 "0" "0x" . "X" 16 ( 0XA06B) . "0" . . "X" 16 .

( scanf()

C scanf . scanf printf . . printf . scanf ("control string", arguments list) ;

scanf ("control string", argl , arg2 ,, arg n) ;

printf . printf . printf %s, %c , %f , %d . "&" .

"&" C ( ) .

( 38 & scanf .

#include

main ()

{ int x ;

char name[6] ;

scanf("%d" , &x) ;

scanf("%s", name) ;

printf("%d %s", x , name) ;

}

scanf x . scanf & name "book" book .

( 33 . 33 scanf ()

.%c

( 10) .%d

.%i

.%u

(floating_point) .%f , %e, %g

(short integer) .%h

. non_white_space white_space ( "\0" ).%s

8 .%0

16 .%x , %X

.%p

( 39 79 .

#include

main () /* read a line of text */

{

char line[80] ;

int count , k ;

/* read in the line */

for (k=0 ; line[k]=getchar ()!=\n ; + +k) count = k ;

for (k=0 ; k

main ()

{

float x = 123.456 ;

printf ("%f %.3f %7.2f" , x , x , x) ;

}6. .

7. .

8. .. format string

. control string