Input and Output

printf()

  1. used to write to the standard output device, usually a monitor
    Example: 
    printf("Hello there!");

  2. included in stdio.h, so use "#include <stdio.h>"
  3. can print the value of variables using placeholders
    Example: 
    printf("My age is %d", MyAge);

    %c char
    %d int
    %f float
  4. Escape sequences must be used for special characters
    \n newline
    \t tab
    \" double quote
    \' single quote
    \? question mark
    \\ backslash

  5. printf() example program: 
    
#include <stdio.h>

int main() {

   int year = 1999;

   printf("This program was written in %d.\n", year);

   return 0;

}
    Source File | DOS Executable (run from DOS prompt)

scanf()

  1. used to read from the standard input device, usually a keyboard
    Example: 
    scanf("%lf",&diameter);  /* wait for input and store it in 
                            a variable named diameter */

    %c char
    %d int
    %lf float
  2. Can be used with multiple inputs.
  3. scanf() example program: 
    
#include <stdio.h>

int main() {

   int year;

   printf("Please enter the year>");

   scanf("%d", &year);

   printf("\n\nThe current year is %d.\n", year);

   return 0;

}
    Source File | DOS Executable (run from DOS prompt)

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