5 iex tricks you should know as an Elixir developer

These tricks will save your time. You will no need to type the same thing again and again, in case of a crash and restarting.

1> v

• if you want data of above line, you can simply do v(-1)
• for output of any particular line, you can v(linenumber) example:

Interactive Elixir (1.11.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> 9
9
iex(2)> 6
6
iex(3)> 12357
12357
iex(4)> v(-1) # give data of iex ( 3 )
12357
iex(5)> v(2) # give data of iex ( 2 )
6
iex(6)> v(-1) # give data of iex ( 5 ) i.e 6
6
iex(7)>

2> dot iex dot exs file iex will check and load for local file in folder as well as global at the root folder.

You can create a .iex.exs file with below content.

morning_greet = "Hi, how are you?"
weekend_greet = "Hi, have a great weekend"
travel_greet = "happy Weekend"

now, start iex and see what happens

➜  watermelon git:(main) ✗ iex -S mix
Erlang/OTP 24 [erts-12.0.3] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [jit]

Interactive Elixir (1.11.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> morning_greet
"Hi, how are you?"
iex(2)> weekend_greet
"Hi, have a great weekend"
iex(3)> travel_greet
"happy Weekend"
iex(4)>

3> multiline, add \ When copying code from editor and posting in command line, you need to add \ to the end of the file.

iex(8)> "abc" |> String.upcase
"ABC"
iex(9)>  "abc"
"abc"
iex(10)> |> String.upcase
** (SyntaxError) iex:10:1: syntax error before: '|>'

iex(10)>  "abc" \
...(10)> |> String.upcase
"ABC"
iex(11)>

4> h

Quickly find documentation for a function using h key.

iex(5)> h Enum.member?

                        def member?(enumerable, element)

  @spec member?(t(), element()) :: boolean()
Checks if element exists within the enumerable.
Membership is tested with the match (===/2) operator.
## Examples
    iex> Enum.member?(1..10, 5)
    true
    iex> Enum.member?(1..10, 5.0)
    false
    iex> Enum.member?([1.0, 2.0, 3.0], 2)
    false
    iex> Enum.member?([1.0, 2.0, 3.0], 2.000)
    true
    iex> Enum.member?([:a, :b, :c], :d)
    false
When not called whithin guards, the in (in/2) and not in (in/2) operators work
by using this function.

5> respawn and recompile. Whenever you make code updates, if you have iex shell open, instead of closing ctrl + c twice and starting iex again, you can just do recompile and new changes will be loaded.

Happy Coding.

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