• ← OptionQ
• → Options

OptionValue

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OptionValue[name]

gives the value of the option name matched by OptionsPattern.

OptionValue[f, name]

recover the value of the option name associated with the head f.

OptionValue[f, opts, name]

recover the value of the option name associated with the symbol f, extracting the values from optvals if available.

OptionValue[..., list]

recover the value of the options in list .

First, set up a symbol with some options using Options:

• • Options[MySetting] = {"foo" -> 5, "bar" -> 6}

Now get a value previously set:

• • OptionValue[MySetting, "bar"]

If the option does exist we get a message:

• • OptionValue[MySetting, "baz"]

Use OptionValue to get the value of option a inside OptionsPattern a->3

• • f[a->3] /. f[OptionsPattern[{}]] -> {OptionValue[a]}

An unavailable option returns argument and does not generate a message:

• • f[a->3] /. f[OptionsPattern[{}]] -> {OptionValue[b]}

The argument of OptionValue must be a symbol:

• • f[a->3] /. f[OptionsPattern[{}]] -> {OptionValue[a+b]}

However, the symbol can be evaluated dynamically:

• • f[a->5] /. f[OptionsPattern[{}]] -> {OptionValue[Symbol["a"]]}

See also Options and OptionsPattern.