E07470: function must have a two parameters

What went wrong

A function or operator requires EXACTLY two parameters but has a different number.

Worked examples

Compilable examples demonstrating this error and the correct fix:

• ek9 -q 124 (How do I group and aggregate collection data in EK9?)

[BINARY OPERATORS (require two parameters)] +, -, *, /, ==, <, >, <=, >=, <>, <=>

How to fix it

1. Provide exactly two parameters

Common causes

• Missing parameter
• Extra parameters

See also

• E07470: two parameters required (this error)
• E07460: single parameter required

Examples

Every example is compiled by the EK9 compiler: the first fails exactly as captioned, the others fix it.

Fails with E07470: function must have a two parameters

#!ek9
defines module error.e07470.bad

  defines function

    byLength()
      -> word as String
      <- rtn as Integer: length word

    sortWords()
      <- rtn as List of String: List()

      //sort compares two items at a time
      cat ["three", "one", "seven"] | sort byLength > rtn

Fixed: Give sort a function of two parameters

#!ek9
defines module error.e07470.good

  defines function

    byLength()
      ->
        first as String
        second as String
      <- rtn as Integer: length first <=> length second

    sortWords()
      <- rtn as List of String: List()
      cat ["three", "one", "seven"] | sort byLength > rtn

Questions and answers

These Q&A entries show E07470 and its fix:

• Q124: How do I group and aggregate collection data in EK9?