JJ logo

Why use JJ?
Designed for beginners


There are many challenges in CS1 both for the students and the teachers.
The students are learning how to program for the first time, which means
that they do not yet know if they are good at or enjoy programming. The
teachers must teach these CS1 students even after many of them discover
that programming is not one of their favorite activities.
  • JJ accepts small initial programs
  • JJ anticipates common errors with curly braces: { and }
  • JJ anticipates common errors with parentheses: ( and )
  • JJ anticipates common errors with semicolons: ;
  • JJ colors syntax
  • JJ has readable error messages