CODEWITHSUNDEEP
julia
user977828
user977828

Reputation: 7679

skip counting by 10 with help of for loop

I would like to get the following values 1, 10, 20, 30, ... but I do not how to do it Julia:

 for (count, x) in enumerate(["x1", "x1.y1", "x1.y1.xyz22", "x133001", "x133001.y1", "x133001.y1.xyz22"])
     println(count + 10 - 1)
 end

What would the best way?

Thank you in advance,

Update

The below code failed to run:

julia> count = 1
1

julia> for x in ["x1", "x1.y1", "x1.y1.xyz22", "x133001", "x133001.y1", "x133001.y1.xyz22"]
           if count == 1
               count = 10
           else
               count += 10
           println(count)
       end


ERROR: syntax: incomplete: "for" at REPL[6]:1 requires end
Stacktrace:
 [1] top-level scope at REPL[5]:0

Upvotes: 0

Views: 822

Answers (2)

Gwang-Jin Kim
Gwang-Jin Kim

Reputation: 10010

For inifinite streams one could use Python-like generators which are available in ResumableFunctions.jl package.

Install by:

using Pkg
Pkg.add("ResumableFunctions")
using ResumableFunctions

Generate an inifnite stream generator function:

@resumable function infstream(start = 0, first_val = 0, step=1)
  "It starts with start value steps by step. However, for first value    
   first_val is returned."
  c = start
  while 1==1
    @yield if (c==start) first_val else c end
    c = c + step
  end
end

You initialize an instance by:

mycount = infstream(0, 1, 10)
mycount() # 1
mycount() # 10
mycount() # 20
# ... etc ad infinitum

For your problem you can use it like this:

counter, result = infstream(0, 1, 10), []
for x in ["x1", "x1.y1", "x1.y1.xyz22", "x133001", "x133001.y1", "x133001.y1.xyz22"]
    push!(result, counter())
end

which gives:

julia> result
6-element Array{Any,1}:
  1
 10
 20
 30
 40
 50

With the resumable infstream() function, you can create any thinkable counters for arithmetic inifinite series.

Upvotes: 1

Bill
Bill

Reputation: 6086

Here is one of an indefinite number of exact solutions. With (count, x) you can mostly use count but use x for the start and end cases:

for (count, x) in enumerate(
    ["x1", "x1.y1", "x1.y1.xyz22", "x133001", "x133001.y1", "x133001.y1.xyz22"]
    )
    if x == "x1"
        print(count, ", ")
    else
        print(10 * (count - 1), ", ")
    end
    if x == "x133001.y1.xyz22"
        println("...")
    end
 end

Gets you: 1, 10, 20, 30, 40, 50, ...

Upvotes: 3

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