HP 3000 Manuals

HP C/iX Reference Manual

The for Statement 

The for statement evaluates three expressions and executes the loop body
until the second expression evaluates to false.

Syntax 

      for ([expression1] ; [expression2]; [expression3]) statement 

Description 

The for statement is a general-purpose looping construct that allows you
to specify the initialization, termination, and increment of the loop.
The for uses three expressions.  Semicolons separate the expressions.
Each expression is optional, but you must include the semicolons.

Expression1 is the initialization expression that typically specifies the
initial values of variables.  It is evaluated only once before the first
iteration of the loop.

Expression2 is the controlling expression that determines whether or not
to terminate the loop.  It is evaluated before each iteration of the
loop.  If expression2 evaluates to a nonzero value, the loop body is
executed.  If it evaluates to 0, execution of the loop body is terminated
and control passes to the first statement after the loop body.  This
means that if the initial value of expression2 evaluates to zero, the
loop body is never executed.

Expression3 is the increment expression that typically increments the
variables initialized in expression1.  It is evaluated after each
iteration of the loop body and before the next evaluation of the
controlling expression.

The for loop continues to execute until expression2 evaluates to 0, or
until a jump statement, such as a break or goto, interrupts loop
execution.

If the loop body executes a continue statement, control passes to
expression3.  Except for the special processing of the continue
statement, the for statement is equivalent to the following:

     expression1; 
     while (expression2) {
        statement 
        expression3; 
     }

You may omit any of the three expressions.  If expression2 (the
controlling expression) is omitted, it is taken to be a nonzero constant.

For example:

          for (i=0; i<3; i++) {
              func(i);
          }

This example calls the function func three times, with argument values of
0, 1, and 2.

MPE/iX 5.0 Documentation