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Extended documentation for mathematical symbols & functions is here.
| symbol | meaning |
|---|---|
@ | the at-sign marks a macro invocation; optionally followed by an argument list |
| ! | an exclamation mark is a prefix operator for logical negation (“not”) |
a! | function names that end with an exclamation mark modify one or more of their arguments by convention |
# | the number sign (or hash or pound) character begins single line comments |
#= | when followed by an equals sign, it begins a multi-line comment (these are nestable) |
=# | end a multi-line comment by immediately preceding the number sign with an equals sign |
$ | the dollar sign is used for string and expression interpolation |
| % | the percent symbol is the remainder operator |
| ^ | the caret is the exponentiation operator |
| & | single ampersand is bitwise and |
| && | double ampersands is short-circuiting boolean and |
| | | single pipe character is bitwise or |
| || | double pipe characters is short-circuiting boolean or |
| ⊻ | the unicode xor character is bitwise exclusive or |
| ~ | the tilde is an operator for bitwise not |
‘ | a trailing apostrophe is the adjoint (that is, the complex transpose) operator Aᴴ |
| * | the asterisk is used for multiplication, including matrix multiplication and string concatenation |
| / | forward slash divides the argument on its left by the one on its right |
| \ | backslash operator divides the argument on its right by the one on its left, commonly used to solve matrix equations |
() | parentheses with no arguments constructs an empty Tuple |
(a,…) | parentheses with comma-separated arguments constructs a tuple containing its arguments |
(a=1,…) | parentheses with comma-separated assignments constructs a NamedTuple |
(x;y) | parentheses can also be used to group one or more semicolon separated expressions |
a[] | array indexing (calling getindex or setindex!) |
[,] | vector literal constructor (calling vect) |
[;] | vertical concatenation (calling vcat or hvcat) |
[ ] | with space-separated expressions, horizontal concatenation (calling hcat or hvcat) |
T{ } | curly braces following a type list that type’s parameters |
{} | curly braces can also be used to group multiple where expressions in function declarations |
; | semicolons separate statements, begin a list of keyword arguments in function declarations or calls, or are used to separate array literals for vertical concatenation |
, | commas separate function arguments or tuple or array components |
? | the question mark delimits the ternary conditional operator (used like: conditional ? if_true : if_false) |
“ “ | the single double-quote character delimits String literals |
“”” “”” | three double-quote characters delimits string literals that may contain “ and ignore leading indentation |
‘ ‘ | the single-quote character delimits Char (that is, character) literals |
| the backtick character delimits external process (Cmd) literals |
A… | triple periods are a postfix operator that “splat” their arguments’ contents into many arguments of a function call or declare a varargs function that “slurps” up many arguments into a single tuple |
a.b | single periods access named fields in objects/modules (calling getproperty or setproperty!) |
f.() | periods may also prefix parentheses (like f.(…)) or infix operators (like .+) to perform the function element-wise (calling broadcast) |
a:b | colons (:) used as a binary infix operator construct a range from a to b (inclusive) with fixed step size 1 |
a:s:b | colons (:) used as a ternary infix operator construct a range from a to b (inclusive) with step size s |
: | when used by themselves, Colons represent all indices within a dimension, frequently combined with indexing |
:: | double-colons represent a type annotation or typeassert, depending on context, frequently used when declaring function arguments |
:( ) | quoted expression |
:a | Symbol a |
| <: | subtype operator |
| >: | supertype operator (reverse of subtype operator) |
= | single equals sign is assignment |
| == | double equals sign is value equality comparison |
| === | triple equals sign is programmatically identical equality comparison |
| => | right arrow using an equals sign defines a Pair typically used to populate dictionaries |
-> | right arrow using a hyphen defines an anonymous function on a single line |
| |> | pipe operator passes output from the left argument to input of the right argument, usually a function |
∘ | function composition operator (typed with \circ{tab}) combines two functions as though they are a single larger function |
