User:Will Gajate/JourneyThroughJ
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As a new J user, I often have trouble recalling the meaning of vocabulary when reading J code. This page serves as a flattened (simple) lookup table for the J language when reading J code and as a mnemonic device for internalizing J.
in-progress
Quick lookup table
Applicable to J.902 x - noun operands of verb (left hand side) y - noun operands of verb (right hand side) u - verb operand of modifier (left hand side) v - verb operand of modifier (right hand side) m - noun operands of modifier (left hand side) n - noun operands of modifier (right hand side)
| name | form | example | result | note |
|---|---|---|---|---|
| self-classify | = y | =i.2 | (1 0;0 1) | deprecated |
| equal | x = y | 2=i.3 | (0 0 1) | |
| is (local) | m =. x | ]z=.1 | 1 | |
| is (global) | m =: x | ]z=:1 | 1 | |
| box | < y | <'ab' | ['ab'] | |
| less than | x < y | 1<i.3 | 0 0 1 | |
| floor | <. y | <.4.6 | 4 | |
| lesser (min) | x <. y | 1<._2 2 | _2 1 | |
| decrement | <: y | <:_5 1 | _6 0 | |
| less or equal | x <: y | 1 10<:8 | 1 0 | |
| open | > y | |||
| larger than | x > y | 1 4>3 | 0 1 | |
| table | x u/ y | (i.3)(*/~)i.2 | (0 0 0;0 1 2) | |
| insert | u/ y | */6 7 | 42 |