This shows you the differences between two versions of the page.
pseudo-variable_20side_20effects [2018/03/31 13:19] 127.0.0.1 external edit |
pseudo-variable_20side_20effects [2018/04/17 18:18] tbest3112 Added syntax highlighting |
||
---|---|---|---|
Line 2: | Line 2: | ||
//by Richard Russell, March 2011//\\ \\ One thing that distinguishes the [[http://www.bbcbasic.co.uk/bbcwin/manual/bbcwin2.html#pseudovars|pseudo-variables]] (**HIMEM**, **LOMEM**, **PAGE**, **PTR#** and **TIME**/**TIME$**) from regular variables is that writing or reading a pseudo-variable may have a //side effect// in addition to what you would expect it to do. So for example a statement like:\\ | //by Richard Russell, March 2011//\\ \\ One thing that distinguishes the [[http://www.bbcbasic.co.uk/bbcwin/manual/bbcwin2.html#pseudovars|pseudo-variables]] (**HIMEM**, **LOMEM**, **PAGE**, **PTR#** and **TIME**/**TIME$**) from regular variables is that writing or reading a pseudo-variable may have a //side effect// in addition to what you would expect it to do. So for example a statement like:\\ | ||
+ | <code bb4w> | ||
LOMEM = LOMEM | LOMEM = LOMEM | ||
+ | </code> | ||
which you might not expect to do anything, actually does have an effect which could be important.\\ \\ The main side effects from accessing the pseudo-variables are listed below:\\ \\ | which you might not expect to do anything, actually does have an effect which could be important.\\ \\ The main side effects from accessing the pseudo-variables are listed below:\\ \\ | ||