Empty Array
< Help(Redirected from Help/Primer/Empty Array)
Jump to navigation
Jump to search
An array is empty if it contains no atoms. An empty array has a 0 in its shape.
a =. 0 $ 0 NB. empty list $a 0 $ '' NB. empty list 0 b =. 2 0 3 $ 'a' NB. empty rank 3 array $b 2 0 3
Empty arrays have no atoms to display and their display can be confusing if you don't know what to expect. An empty list displays as a blank line. A table with 0 rows displays as 0 lines; a table with 3 rows, but 0 columns, displays as 3 blank lines.
2 $ 5 5 5 1 $ 5 5 0 $ 5 NB. empty list displays as blank line 2 2 $ 5 5 5 5 5 1 2 $ 5 5 5 2 0 $ 5 NB. 2 rows displays 2 lines 0 2 $ 5 NB. 0 rows displays 0 lines
The display of lists and tables with 1 row can look the same, and you have to look at their shape to distinguish them.
a =. 2 $ 5 b =. 1 2 $ 5 a 5 5 b NB. b displays the same as a 5 5 $ a 2 $ b NB. but b has a different shape 1 2
Primer Index Hover to reveal titles - Click to access - Current page is highlighted | ||||||||||||||||||||||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | ✅ |
26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | ✅ | ||||||
45 | 46 | 47 | 48 | ✅ | ||||||||||||||||||||
50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | ✅ | ||||||||||||||||
59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | ✅ | |||||||
77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | ✅ | |||||
97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | ✅ |