Info Catalog eintr: Incrementing Loop eintr: while eintr: Decrementing Loop

eintr: Incrementing Loop Details

 
 Details of an Incrementing Loop
 -------------------------------
 
 The test for a loop with an incrementing counter can be an expression
 such as ‘(< count desired-number)’ which returns ‘t’ for true if the
 value of ‘count’ is less than the ‘desired-number’ of repetitions and
 ‘nil’ for false if the value of ‘count’ is equal to or is greater than
 the ‘desired-number’.  The expression that increments the count can be a
 simple ‘setq’ such as ‘(setq count (1+ count))’, where ‘1+’ is a
 built-in function in Emacs Lisp that adds 1 to its argument.  (The
 expression ‘(1+ count)’ has the same result as ‘(+ count 1)’, but is
 easier for a human to read.)
 
    The template for a ‘while’ loop controlled by an incrementing counter
 looks like this:
 
      SET-COUNT-TO-INITIAL-VALUE
      (while (< count desired-number)         ; true-or-false-test
        BODY...
        (setq count (1+ count)))              ; incrementer
 
 Note that you need to set the initial value of ‘count’; usually it is
 set to 1.
 

Menu

 
· Incrementing Example        Counting pebbles in a triangle.
· Inc Example parts           The parts of the function definition.
· Inc Example altogether      Putting the function definition together.
 

Info Catalog eintr: Incrementing Loop eintr: while eintr: Decrementing Loop