NSString compare:options:range: - which value to pass for no options?
I want to call [NSString compare:options:range:] and pass no options.
What should be the correct value to prov开发者_JAVA技巧ide for the options parameter?
Both nil and NULL produce a warning in Xcode : "Incompatible pointer to integer conversion sending 'void *' to parameter of type ... "
Just pass 0
. Alternatively, if you've been around the Mac block a few times, you might catch yourself passing kNilOptions
which is just another name for 0
, but implies the relevant flagginess.
You should pass 0
. The options
argument is a bit mask, which really means it's just an integer. That's also why the warning says "integer conversion".
As Apple Docs says:
Options for the search—you can combine any of the following using a C bitwise OR operator: NSCaseInsensitiveSearch, NSLiteralSearch, NSNumericSearch. See String Programming Guide for details on these options.
NSCaseInsensitiveSearch
: A case-insensitive search.
NSLiteralSearch
: Exact character-by-character equivalence.
NSNumericSearch
: Numbers within strings are compared using numeric value, that is, Name2.txt < Name7.txt < Name25.txt.
String Programming Guide
精彩评论