 Ruby
        Ruby  
      Ruby初心者必見!ぼっち演算子の完全解説と7つの使用例    
   Ruby
        Ruby   JS
        JS   C++
        C++   Python
        Python   Swift
        Swift   Ruby
        Ruby   Python
        Python   Perl
        Perl   CSS
        CSS   Verilog
        Verilog   HTML
        HTML   JS
        JS   COBOL
            COBOL     Ruby
            Ruby     CSS
            CSS     C++
            C++     Dart
            Dart     C++
            C++     Python
            Python     C++
            C++     HTML
            HTML     C++
            C++