# `FunctionClauseError`
[🔗](https://github.com/elixir-lang/elixir/blob/6fd161d67d4e62a3d3cbc99b05483177c3172b24/lib/elixir/lib/exception.ex#L1927)

An exception raised when a function call doesn't match any defined clause.

For example:

    iex> List.duplicate(:ok, -3)
    ** (FunctionClauseError) no function clause matching in List.duplicate/2

The following fields of this exception are public and can be accessed freely:

  * `:module` (`t:module/0`) - the module name
  * `:function` (`t:atom/0`) - the function name
  * `:arity` (`t:non_neg_integer/0`) - the arity of the function

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*Consult [api-reference.md](api-reference.md) for complete listing*