What ⍴ means
The APL reshape operator reports dimensions or reshapes an array.
An APL array is a list or grid of values; ⍴Y reports its dimensions.
How did APL begin?
Kenneth Iverson began developing APL in 1957; its first known account appeared in 1960. His 1962 book A Programming Language set out the notation. APL began as mathematical notation for data processing and became a programming language.
Don't confuse it with
1
Combination ideas
3Reports Y’s dimensions.
Reshapes Y to dimensions X.
Gives how many dimensions Y has.
Questions people ask
1Why does ⍴ show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
More like this
9
How to type or find ⍴
- Search it as
- APL · rho · reshape · APL keyboard
- Shows up in
- Anything that takes text · its shape is whatever your font draws
Windows (Word)
Windows
HTML
⍴CSS
\2374APL layout or RIDE
Use APLR on a configured APL layout (Ctrl/Alt/AltGr), or Dyalog RIDE’s prefix key then R; its language bar lists shortcuts.
Codes and encoding1 code points
HTML decimal
⍴
HTML hex
⍴
CSS content
content: "\2374";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%8D%B4
1
On screen
1
Code points
1
JS .length
3
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.