Tells if all letter characters in "str" match the condition checked by "check". "check" must be something that takes a character in the first argument and returns an integer type where a value different from 0 means that the condition is satisfied.
string to convert
true if all letter characters match the the condition checked by "check" or false otherwise
See Implementation
Tells if all letter characters in "str" match the condition checked by "check". "check" must be something that takes a character in the first argument and returns an integer type where a value different from 0 means that the condition is satisfied.