Input and Output

Introduce I/O early, so we can run programs and see something happen :-)

Example

      #include <stdio.h>

      /* Read and print three floating point numbers */

      int main()
      {
        float a, b, c;

        /* Input */
        scanf ("%f %f %f", &a, &b, &c);

        /* Output */
        printf ("%f, %f, %f\n", a, b, c);

        return (0);
      }

• stdio.h is header file containing definitions of macros and variables used by the I/O system

• a, b and c are floating point variables

• scanf reads formatted input from stdin, i.e. the keyboard

• "%f" denotes format conversion to float

• "&" denotes the address of the variable to be passed to the input function (and not a copy of the value)

• printf prints formatted output to stdout, i.e. the screen

• "\n" denotes the end-of-line character