What happen to string.ToCommonSenseCase()?

Question

I'm very confused about this. In most programming languages, there are string.ToUpperCase(), string.ToLowerCase(), sometimes Capitalize() (which capitalize the first letter of the string), even ToTitleCase() which capitalize every first letter of everyword.

But why isn't there any ToCommonSenseCase()? The one that capitalize the first letter of each sentence? Why doesn't any language have it? I thought it should be the first utility function to implement case-wise.

Answer 1

That's called sentence case, and there are some challenges with it:

• The word "I" needs to be capitalized, wherever it appears in the sentence. Granted, the programming language could detect that.
• Proper nouns ('names') always need to be capitalized. These are a lot harder to detect programmatically; a dictionary alone won't even help since "Mark" is both a name and a common word.
• A dot does not always signify the end of a sentence, e.g. when using abbreviations like this sentence does.
• Other languages than English have different capitalization rules: for example, German capitalizes all nouns.

You see that a proper sentence casing tool is much more complicated that just transforming each letter to capital or lowercase form; that's why standard libraries don't have this functionality.