All the Input/Output operations are carried out through functions calls such as printf() and scanf()
scanf()
- General purpose console input function. Also used to input a data line containing mixed mode data.
- syntax : scanf ("format specifier", variable_list); // end with semi-colon and case-sensitive.
- 'format specifier' specifies the field format in which the data has to be entered.
- 'variable list' specifies the address of the location where the data is stored.
- use '%' before format sepecifier and '&' before a variable name
Format Specifier
- It contains specifications for the interpretation of input data.
- '%' conversion character.
- list of format specifier
- %c To read a single character
- %d To read a decimal integer
- %e To read a floating point value
- %f To read a floating point number
- %g To read a floating point value
- %o to read an octal value
- %x To read an Hexadecimal value
- %s To read a String
- %u To read an unsigned integer
- For reading a string
- scanf("%s", &st); // st contains the string value
- For reading two values
- scanf("%d,%d",&a,&b);\
- Features :
- format specification and variable list must correctly match the same order
- The format specifier must be separated by space or comma and vairable list by comma
- use of invalid match between format specifier and variable list will make the scanf() to terminate the reading of data
printf()
- syntax : printf ( " format specifier ", variable list);
- never takes the print to the new line so we use '\n' for a new line
- eg : printf(" no of chocolates = %d \n no of sweets = %d",&a,&b); // ouput : no of chocolates = 12 [next line ] no of sweets = 13 // where a = 12 and b =13
- list of escape sequences like \n
- \b back space
- \f Form feed
- \n New line
- \r Carriage return
- \t Horizontal tab
- \" Double quote mark
- \' single quote mark
- \0 null
- \\ Back slash
- \v Vertical tab
- \a Alert ( rings a bell)
- \o Octal constant
- \x Hexadecimal constant
Sample Program :
First you need :
Compiler :
online compiler : codepad.org
offline compiler : http://edn.embarcadero.com/article/20633 (borlan c++ compiler)
http://www.digitalmars.com/ (digital mars c compiler)
01 #include <stdio.h> // imports the header file stdio.h which contains the definitions of scanf() and printf()
functions.
02 void main() // execution of the program begins in the main() function
03 {
04 printf(" Hello world ");
05 } // main() ends here
output : Hello world
Next Article : Programming in C - 3. Control Statements and Arrays
