NSStrikethroughStyleAttributeName
is available from iOS 6 so if you are supporting 6 and above you have no worries.
Apple also uses weak linking. This sets symbols that aren't available in the current version of the OS to NULL
. So, you can test the symbol to see if it exists with:
if (NSStrikethroughStyleAttributeName != nil) {
// use NSStrikethroughStyleAttributeName
}