input output management in c programming

Compiled By: Kamal Acharya

PRINTF(), SCANF()CONVERSION SPECIFIERSESCAPE SEQUENCES

Input Output Management


INPUT and OUTPUT


printf() will print formatted output to the screen.

To print a message: printf("This is a message\n");

How do we print the value of a variable? Answer: Use special format specifiers depending on the

type of the variable

this is a string literal

Printing Output: printf()


int degreesF = 68;printf("The temperature is %d degrees.", degreesF);

Specifier for“print an integer value”

“and the value of that number is read from this variable”

> The temperature is 68 degrees.

Output:


int a = 1;int b = 2;int c = 3;

printf(“%d plus %d is equal to %d", a, b, c);

1 plus 2 is equal to 3

Output:


Format specifiers: %c for single characters %d for integers %f for float/double (fractions): 1234.56 %g for float/double (scientific): 1.23456E+3 %s for phrases or ‘strings’


Output:

A 65 41 101

Example:char a='A';printf("%c %d %x %0", a, a, a, a);


Format specifier can be used with modifiers

Example :%-6d, %5d, %6.2f

Modifier

digit

Description

Allocate minimum width (in characters).

.digit Number of floating-points

- left justified

l Print the data as a long integer.


Statement Output

printf("|%d|", 987); |987|

printf("|%2d|", 987); |987|

printf("|%8d|", 987); | 987|

printf("|%-8d|", 987); |987 |

printf("|%0.2f|", 9876.54); |9876.54|

printf("|%4.2f|", 9876.54); |9876.54|

printf("|%3.1f|", 9876.54); |9876.5|

printf("|%10.3f|", 9876.54); | 9876.540|


printf(“Hello \n World!");

Hello World!

Output:

‘\n’ is not a data to be printed. Instead, it is a command that tells the monitor to move the cursor to the next line


Control Characters (Escape Sequences)

Character

'\n''\t''\v''\r'

'\x41''\101''\0'

'\'''\"''\\''\b''\f''\a'

Description

newlinehorizontal tabvertical tabcarriage returnhexadecimal number, 0x41octal number 101null character - indicates the end of a string

single quatation mark (')double quatation mark (")backslash mark (\)backspaceformfeed - next page (used for printer)alert - produce a beep sound


Figure: Output specification for inventory report

printf (“Part Number\tQty On Hand\tQty On Order\t\tPrice\n”);

\t \t \t\t \n


Keyboard input: scanf()

scanf() will scan formatted input from the keyboard. It uses the same format specifiers as printf() To read an integer:

int num_students;scanf("%d", &num_students);

Specifier for“reading an integer value”

VERY IMPORTANTspecial symbol

“Place value into this variable”


Format specifiers for scanf()

Format specifiers: %c for single characters

scanf(" %c", &some_character);

%d for integers scanf ("%d", &some_integer);

%f for float scanf ("%f", &some_float);

%lf for double scanf ("%lf", &some_double);

always put a space between " and % when reading characters


Escape Sequences

input output management in c programming

Education