CodePudding user response:
Clear may need knowledge:1. The function of "- & gt;" Said, there is a return value of functions;
2. Call returns a value function, if do not deal with the return value, can use "_" to deal with, so, the compiler will not report warning;
Problem description:
1. "printAndCount" function is a return value, and the return value is an Int type;
2. "printWithoutCounting" function is not return a value;
3. "printWithoutCounting function calls the" printAndCount "internal", and use "let _" receiving treatment (to avoid a compiler warning);
4. The function of print, call it either directly or indirectly invoked, will print, all will print "hello, world";
The hope can help topic main,
CodePudding user response:
The second function is not the first function called? Just ignore the return value, nothing special