Operator Reference
while (Operator)
while
— Starts a loop block that is executed as long as the condition is true.
Signature
while( : : Condition : )
Description
while
executes the loop body up to the corresponding
endwhile
statement as long as the Condition
parameter
evaluates to 'true' (or a number not equal 0).
If the condition evaluates to 'false' (0) the program is
continued after the corresponding endwhile
statement.
Parameters
Condition
(input_control) integer →
(integer)
Condition for loop.
Example (HDevelop)
dev_update_window ('off') dev_close_window () dev_open_window (0, 0, 512, 512, 'black', WindowID) read_image (Image, 'particle') dev_display (Image) stop () threshold (Image, Large, 110, 255) dilation_circle (Large, LargeDilation, 7.5) dev_display (Image) dev_set_draw ('margin') dev_set_line_width (3) dev_set_color ('green') dev_display (LargeDilation) dev_set_draw ('fill') stop () complement (LargeDilation, NotLarge) reduce_domain (Image, NotLarge, ParticlesRed) mean_image (ParticlesRed, Mean, 31, 31) dyn_threshold (ParticlesRed, Mean, SmallRaw, 3, 'light') opening_circle (SmallRaw, Small, 2.5) connection (Small, SmallConnection) dev_display (Image) dev_set_colored (12) dev_display (SmallConnection) stop () dev_set_color ('green') dev_display (Image) dev_display (SmallConnection) Button := 1 while (Button == 1) dev_set_color ('green') get_mbutton (WindowID, Row, Column, Button) dev_display (Image) dev_display (SmallConnection) dev_set_color ('red') select_region_point (SmallConnection, SmallSingle, Row, Column) dev_display (SmallSingle) NumSingle := |SmallSingle| if (NumSingle == 1) intensity (SmallSingle, Image, MeanGray, DeviationGray) area_center (SmallSingle, Area, Row, Column) dev_set_color ('yellow') set_tposition (WindowID, Row, Column) write_string (WindowID, 'Area='+Area+', Int='+MeanGray) endif endwhile dev_set_line_width (1) dev_update_window ('on')
Result
If the values of the specified parameters are correct,
while
(as operator) returns 2 (
H_MSG_TRUE)
. Otherwise, an
exception is raised and an error code returned.
Alternatives
See also
repeat
,
break
,
continue
,
if
,
elseif
,
else
Module
Foundation