From Ver6 onwards, there is no distinction between full-width and half-width characters. Please note that the operation is different from Ver5.
 
Example)

var a = ::StrLen("aiu abc");

In Ver5, "aiu" is full-width and abc is half-width, so the return value of StrLen is 9. From Ver6 onwards, there is no distinction between half-width and full-width, so the return value of StrLen is 6.