operator OR on char port to java

operator OR on char port to java

Hello could any one could explain me this line of code written in c++?
couleur[i][c]=couleur[i][c] ||
couleur[noeud][c];
Arrays are char type. What does this or do? ( arrays indexes are
meaningless so i don't explain them), because i need to rewrite this line
to Java code and in Java i got error "bad operand types for binary ||". I
checked this code in c++ and can get what it does - doesn't matter what
value chars get it always assign ' '.
Any idea?