My code has three errors. Fix them all with minimal changes.

Here are the three fixes:

1. Change := to <- on line where greeting is first created.

   greeting := "Hello"  becomes  greeting <- "Hello"
   Reason: := updates existing variables. <- creates new ones. Using := on a new name is E50001 (not resolved).

2. Recommendation (not a compile error): add 'as pure' to the function that has no side effects.

   formatName()  becomes  formatName() as pure
   Reason: functions that only compute from inputs should be pure - the code compiles without it, but pure gives the compiler and readers a guarantee.

3. Change the return variable type initialisation.

   <- rtn as String?  becomes  <- rtn as String: String()
   Reason: a return value must be initialised on every path. Without the initialiser the compiler reports E08050 (return value is not always initialised) because the if has no else. String() creates an unset String.

Each fix is one small change. Do not restructure the code or add features — just fix the errors (fixes 1 and 3) and apply the recommendation (fix 2) only if asked.

Example

defines module qa.gettingstarted.multistepfix

  defines function

    formatName() as pure
      -> name as String
      <- rtn as String: String()

      if name?
        rtn := "Dear " + name

  defines program

    MultiStepFixDemo()
      stdout <- Stdout()

      greeting <- "Hello"
      stdout.println(greeting)

      formatted <- formatName("Alice")
      stdout.println(formatted)

Common mistakes

E50001 — Use <- to create a new variable. The := operator expects the variable to already exist.

Incorrect:

      greeting := "Hello"

Correct:

      greeting <- "Hello"

Other ways to ask this

Fix these multiple errors in my EK9 code
Quick fix: several mistakes in one function
Correct all the problems in this code at once

Coming from another language?

EK9 error fixing is incremental. Fix one error at a time. The compiler will guide you to the next one.

Keywords: multiple, quick, generalist, minimal, fix, errors