Function Repository Resource:

SwapCase

Source Notebook

Convert uppercase letters to lowercase and vice versa

Contributed by: Sander Huisman

ResourceFunction["SwapCase"][string]

converts uppercase letters in string to lowercase and vice versa.

Examples

Basic Examples (1)

Swap the cases in a string:

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Scope (1)

SwapCase automatically threads over a list of strings:

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Properties and Relations (2)

SwapCase can be programmed by using LowerCaseQ or UppercaseQ and the functions ToUpperCase and ToLowerCase:

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The implementation of SwapCase is many times faster, though:

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Possible Issues (2)

For nearly all strings, SwapCase is an involutory function:

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There are a few exceptions:

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$chars = {"\[Micro]", "ß", "ÿ", "ı", "Ÿ", "ſ", "\[FinalSigma]", "\:03d0", "\[CurlyTheta]", "\[Phi]", "\[CurlyPi]", "\[CurlyKappa]", "\[CurlyRho]", "\:03f4", "\[Epsilon]", "ẛ", "ẞ", "ᾀ", "ᾁ", "ᾂ", "ᾃ", "ᾄ", "ᾅ", "ᾆ", "ᾇ", "ᾐ", "ᾑ", "ᾒ", "ᾓ", "ᾔ", "ᾕ", "ᾖ", "ᾗ", "ᾠ", "ᾡ", "ᾢ", "ᾣ", "ᾤ", "ᾥ", "ᾦ", "ᾧ", "ᾳ", "ι", "ῃ", "ῳ", "Ω", "K", "\[DotlessJ]", "\[FormalSigma]", "\[FormalCurlyTheta]", "\[FormalPhi]", "\[FormalCurlyPi]", "\[FormalCurlyKappa]", "\[FormalCurlyRho]", "\[FormalEpsilon]"}; ResourceFunction["SwapCase"]@*ResourceFunction["SwapCase"]@chars$