10 Julia Recipes You Can't Miss

function sum1(a, remaining...)
    sm = a + sum(remaining)
    println(sm)
end

sum1(1, 2, 3, 4,5)
sum1(1)
sum1(1,2,3)

stri = "I scream, you scream, we all scream for ice cream."
stri = replace(stri, "scream" => "cry")
println(stri)
stri = "I scream, you scream, we all scream for ice cream."
replace(stri, "scream"=>uppercase) #replace scream by SCREAM

temp = [56, 49, 50, 55, 53, 52, 60, 60, 42, 54]

# Only the elements that are greater than 50
filtered = [item for item in temp if item > 50]
print(filtered)

filtered = filter(>(50), temp)

filtered = filter(temp) do x
    x > 50
end

temp1 = (45, 51, 43, 49, 47)
a, b, c, d, e = temp1
print(a)
print(d)

stri = "Money"
c1, c2, c3, c4, c5 = stri

t = (a=1, b="hello", c = 3.14) #named tuple
(; a, c) = t; @show a; @show c; #a = 1,c = 3.14,b undefined

marks = Dict("Ram" => 60, "Shyam" => 33, "Manik" => 64,"Mani" => 76, "Hema" => 84)

more_than_55 = Dict(key => value for (key, value) in marks if value > 60)
println(more_than_55)

names = Set(["Ram", "Hema", "Mani","Manik"])
selected = Dict(key => value for (key, value) in marks if key in names)
println(selected)

for i in reverse(1:5)
  print(i)
end

r = reverse("Julia")
"ailuJ"

for i in 1:length(r)
  print(r[reverseind("Julia", i)])
end

str = "Julia's syntax is good"
println(lpad(str, 40, '*'))
******************Julia's syntax is good
println(rpad(str, 40, '*'))
Julia's syntax is good******************

function retMultipleValues()
    v1,v2 = "India","Iran"
    return v1,v2
end

countries = retMultipleValues()
println(countries)

fid = open("abc.txt", "x") #"x" flag ensures that the file is created only if it does not already exist. 
write(fid, "Hello Julia")
close(fid)

open("def.txt", "w") do fid #no need for close statement
    write(fid, "Hey")
end

#Read a text file line by line
for line in eachline("my_file.txt")
    print(line)
end

#most compact
foreach(println,eachline("my_file.txt"))

readlines("my_file.txt")

using Dates

dstr = "2023-07-03"
println(typeof(dstr))

date_time = DateTime(dstr, "yyyy-mm-dd")
println(date_time)
println(typeof(date_time))

points = [(x=rand(), y=rand()) for i in 1:10]
distances = [sqrt(p.x^2 + p.y^2) for p in points if p.x > p.y]
#distances = [hypot(p.x , p.y) for p in points if p.x > p.y]

julia> a, b..., c = (1, 2, 3, 4)
(1, 2, 3, 4)

julia> a
1

julia> b
(2, 3)

julia> c
4

julia> r = join([1,2,3.1], ", ")
"1.0, 2.0, 3.1"

julia> round(Int, 12.5) == Int(trunc(12.5))
true

parse(Int, "1011", base=2) 

 join(rand(['1','0'],10))

B = [1 2 3 4]
1×4 Matrix{Int64}:
 1  2  3  4
julia> dropdims(B,dims=1)
4-element Vector{Int64}:
 1
 2
 3
 4
vec(B)
4-element Vector{Int64}:
 1
 2
 3
 4

B = [1 2 3 4]
1×4 Matrix{Int64}:
 1  2  3  4
julia> permutedims(B)
4×1 Matrix{Int64}:
 1
 2
 3
 4

a = [1,2,3]
in(1,a) # true

a = [1,2,3]
splice!(a,2)
a
[1,3]

colors = ['R','G']
n = 3
vec(Iterators.product(fill(colors, n)...) |> collect)
8-element Vector{Tuple{Char, Char, Char}}:      
 ('R', 'R', 'R')                                
 ('G', 'R', 'R')                                
 ('R', 'G', 'R')                                
 ('G', 'G', 'R')                                
 ('R', 'R', 'G')                                
 ('G', 'R', 'G')                                
 ('R', 'G', 'G')                                
 ('G', 'G', 'G')                                

x = raw"C:/temp"

x = 3 > 2 && 7 #x = 7
x = 2 > 3 && 7 #x = false

readdir(raw"C:\temp") 

for (root,fold,files) in walkdir(raw"C:\temp") 
  for f in files                                                                            
    println(joinpath(root,f))  #print all full file paths (python os.walk)                                                                 
  end                                                                 
  end 
end      

julia> using DelimitedFiles

julia> a = rand(2,3);

julia>  writedlm(stdout, a)
0.29272827910923105     0.7551746399784662      0.22809145708060086
0.9698016822675571      0.7551356902700419      0.740811475230424

 indices = findall(x -> x < 0, -4:10)

import LinearAlgebra as la

filter!(!=(1), [1,0,1,2,4])

A = Matrix{Any}(rand(2,2))
B = similar(A,Float64)
B .= A

a = 2
typeof(a)
a isa Int64
eltype(a)

hexStr = Meta.parse(string("0b", bitstring(1.0f0)))
0x3f800000
reinterpret(Float32,hexStr)
1.0f0
reinterpret(UInt8,[1.0f0])
4-element reinterpret(UInt8, ::Vector{Float32}):
 0x00
 0x00
 0x80
 0x3f

x = rand(1024)
y =  x[1:end÷2] #y = x[1:512]

run(`$(Base.julia_cmd())`)