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authorLilian Besson <Naereen@users.noreply.github.com>2021-01-28 17:46:32 +0100
committerGitHub <noreply@github.com>2021-01-28 17:46:32 +0100
commitee6d01987215f3da6e52628d09679cadd26c10e5 (patch)
treee5fdcfa3239e5f2372430740b2d50b4af2cc51a3
parente4d44a37712bfde3862b0afc59bff7e1594ef60e (diff)
Small update on julia.html.markdown, typos and comments
Small update on julia.html.markdown, typos and comments
-rw-r--r--julia.html.markdown65
1 files changed, 34 insertions, 31 deletions
diff --git a/julia.html.markdown b/julia.html.markdown
index 5e9ef1b8..4d8eb497 100644
--- a/julia.html.markdown
+++ b/julia.html.markdown
@@ -11,7 +11,7 @@ Julia is a new homoiconic functional language focused on technical computing.
While having the full power of homoiconic macros, first-class functions,
and low-level control, Julia is as easy to learn and use as Python.
-This is based on Julia 1.0.0
+This is based on Julia version 1.0.0.
```julia
# Single line comments start with a hash (pound) symbol.
@@ -83,7 +83,7 @@ false
1 > 10 # => false
2 <= 2 # => true
2 >= 2 # => true
-# Comparisons can be chained
+# Comparisons can be chained, like in Python but unlike many other languages
1 < 2 < 3 # => true
2 < 3 < 2 # => false
@@ -93,28 +93,29 @@ false
# Character literals are written with '
'a'
-# Strings are UTF8 encoded. Only if they contain only ASCII characters can
-# they be safely indexed.
-ascii("This is a string")[1]
+# Strings are UTF8 encoded, so strings like "π" or "☃" are not directly equivalent
+# to an array of single characters.
+# Only if they contain only ASCII characters can they be safely indexed.
+ascii("This is a string")[1] # => 'T'
# => 'T': ASCII/Unicode U+0054 (category Lu: Letter, uppercase)
-# Julia indexes from 1
+# Beware, Julia indexes everything from 1 (like MATLAB), not 0 (like most languages).
# Otherwise, iterating over strings is recommended (map, for loops, etc).
-# String can be compared lexicographically
-"good" > "bye" # => true
+# String can be compared lexicographically, in dictionnary order:
+"good" > "bye" # => true
"good" == "good" # => true
"1 + 2 = 3" == "1 + 2 = $(1 + 2)" # => true
-# $ can be used for string interpolation:
+# $(..) can be used for string interpolation:
"2 + 2 = $(2 + 2)" # => "2 + 2 = 4"
# You can put any Julia expression inside the parentheses.
# Printing is easy
-println("I'm Julia. Nice to meet you!") # => I'm Julia. Nice to meet you!
+println("I'm Julia. Nice to meet you!") # => I'm Julia. Nice to meet you!
# Another way to format strings is the printf macro from the stdlib Printf.
-using Printf
-@printf "%d is less than %f\n" 4.5 5.3 # => 5 is less than 5.300000
+using Printf # this is how you load (or import) a module
+@printf "%d is less than %f\n" 4.5 5.3 # => 5 is less than 5.300000
####################################################
@@ -123,7 +124,7 @@ using Printf
# You don't declare variables before assigning to them.
someVar = 5 # => 5
-someVar # => 5
+someVar # => 5
# Accessing a previously unassigned variable is an error
try
@@ -137,9 +138,10 @@ end
SomeOtherVar123! = 6 # => 6
# You can also use certain unicode characters
+# here ☃ is a Unicode 'snowman' characters, see http://emojipedia.org/%E2%98%83%EF%B8%8F if it displays wrongly here
☃ = 8 # => 8
-# These are especially handy for mathematical notation
-2 * π # => 6.283185307179586
+# These are especially handy for mathematical notation, like the constant π
+2 * π # => 6.283185307179586
# A note on naming conventions in Julia:
#
@@ -171,7 +173,7 @@ matrix = [1 2; 3 4] # => 2×2 Array{Int64,2}: [1 2; 3 4]
b = Int8[4, 5, 6] # => 3-element Array{Int8,1}: [4, 5, 6]
# Add stuff to the end of a list with push! and append!
-# By convention, the exclamation mark '!'' is appended to names of functions
+# By convention, the exclamation mark '!' is appended to names of functions
# that modify their arguments
push!(a, 1) # => [1]
push!(a, 2) # => [1,2]
@@ -202,10 +204,10 @@ a # => [7,2,4,3,4,5,6]
# Function names that end in exclamations points indicate that they modify
# their argument.
arr = [5,4,6] # => 3-element Array{Int64,1}: [5,4,6]
-sort(arr) # => [4,5,6]
-arr # => [5,4,6]
-sort!(arr) # => [4,5,6]
-arr # => [4,5,6]
+sort(arr) # => [4,5,6]
+arr # => [5,4,6]
+sort!(arr) # => [4,5,6]
+arr # => [4,5,6]
# Looking out of bounds is a BoundsError
try
@@ -238,7 +240,7 @@ a = [1:5;] # => 5-element Array{Int64,1}: [1,2,3,4,5]
a2 = [1:5] # => 1-element Array{UnitRange{Int64},1}: [1:5]
# You can look at ranges with slice syntax.
-a[1:3] # => [1, 2, 3]
+a[1:3] # => [1, 2, 3]
a[2:end] # => [2, 3, 4, 5]
# Remove elements from an array by index with splice!
@@ -276,15 +278,15 @@ in(2, tup) # => true
# You can unpack tuples into variables
a, b, c = (1, 2, 3) # => (1,2,3)
-a # => 1
-b # => 2
-c # => 3
+a # => 1
+b # => 2
+c # => 3
# Tuples are created even if you leave out the parentheses
d, e, f = 4, 5, 6 # => (4,5,6)
-d # => 4
-e # => 5
-f # => 6
+d # => 4
+e # => 5
+f # => 6
# A 1-element tuple is distinct from the value it contains
(1,) == 1 # => false
@@ -292,8 +294,8 @@ f # => 6
# Look how easy it is to swap two values
e, d = d, e # => (5,4)
-d # => 5
-e # => 4
+d # => 5
+e # => 4
# Dictionaries store mappings
emptyDict = Dict() # => Dict{Any,Any} with 0 entries
@@ -375,7 +377,8 @@ end
# Iterable types include Range, Array, Set, Dict, and AbstractString.
for animal = ["dog", "cat", "mouse"]
println("$animal is a mammal")
- # You can use $ to interpolate variables or expression into strings
+ # You can use $ to interpolate variables or expression into strings.
+ # In this special case, no need for parenthesis: $animal and $(animal) give the same
end
# => dog is a mammal
# => cat is a mammal
@@ -408,7 +411,7 @@ end
let x = 0
while x < 4
println(x)
- x += 1 # Shorthand for x = x + 1
+ x += 1 # Shorthand for in place increment: x = x + 1
end
end
# => 0