5.3.1 Variable Initialization

Local and global variables can be initialized when they are declared. If no initialization value is given, the variable is initialized to zero.

    int foo()
    {
      int x;        /* create local variable x
                       with initial value 0    */
      int y= 7;     /* create local variable y
                       with initial value 7    */
      ...
    }

    float z=3.0;    /* create global variable z
                       with initial value 3.0  */

Local variables are initialized whenever the function containing them runs.

Global variables are initialized whenever a reset condition occurs. Reset conditions occur when:

1. New code is downloaded;
2. The main() procedure is run;
3. System hardware reset occurs.