Category: computer science

Programming: Java file runs w/o compiling

Self-tutoring about Java: the tutor mentions an interesting observation. This morning, on this computer, I updated Java to openjdk-13. Having done so, I wrote a small class file to test the installation. On the command line I forgot to compile,

Graphics: aliasing and anti-aliasing

Self-tutoring about graphics: the tutor mentions the concepts of aliasing and anti-aliasing. Aliasing refers to the jagged “stairway” pattern that can develop on a computer-generated curve or oblique line. It can occur when visual units are squares whose edges are

Windows: folder has different name in Windows Explorer vs directory in Command Prompt

Self-tutoring about Windows file system: the tutor mentions a discovery. Today, checking a backup directory, I noticed that, in Windows Explorer, the backup folder for Desktop (desktop_backup) isn’t there. Rather, Desktop is. Yet, in command prompt, Desktop isn’t there, but

Notepad++: using regular expression to search and replace

Self-tutoring about Notepad++: the tutor mentions using regular expressions. Regular expressions can be used in Notepad++ Search and Replace. For instance, suppose you want to change the variable names test2 test39 test991 to test_2 test_39 test_991 . In Notepad++, such

Text editors: Notepad++, part 1: copy current line shortcut

Self-tutoring about computer science apps: the tutor mentions a trick. In my experience, the shortcut to copy current line, Notepad++: Crtl+Shift+X The version of Notepad++ I use is v7.5.9 Source:

Text editors: Notepad++: how to retrieve the cursor

Self-tutoring about Notepad++: the tutor mentions a way to restore the cursor. Once or twice, while using Notepad++, I’ve had the cursor disappear. Last time, I retrieved it by going Settings→Preferences→Editing→Caret Settings, then setting Width to Block. Source:

Computer science: what is a search mask?

Self-tutoring about computer science terminology: the tutor mentions “search mask”. As I understand: search mask (n): a pattern that matches must follow. The masked parts are variable, possibly indicated by wildcards. An example might be qu#te, # being the wildcard.

Perl: can a computer understand “or” the way a human does?

Self-tutoring about computer science: the tutor explores the concept of “or”. In English, “or” means a choice: ham or bacon, for instance. In computer science, “or” is often called a logical operator, implying it yields 1 if true, but 0

Webpack: how to get installed version

Self-tutoring about computer science: the tutor mentions a way to find the installed version of webpack. npm list webpack is the way I’ve found works. I run Webpack in Node on Windows. Source:

Perl: ternary operator

Perl self-tutoring: the tutor mentions the ternary operator. Let’s imagine the variable $v0 is not defined, and therefore false from Perl’s point of view. $v0 ? print ‘defined’ : print ‘not defined’ will output not defined. a?b:c is known as