IN OUT Mode
An IN OUT parameter passes initial values to the subprogram being called and return efficient values to the caller. Within the subprogram, an IN OUT parameter acts such an initialized variable. And hence, it can be assigned a value and its value can be assigned to the other variable. The actual parameter which corresponds to an IN OUT formal parameter should be a variable; it cannot be a constant or an expression. When you exit a subprogram effectively, the PL/SQL assigns values to the actual parameters. Though, if you exit with an unhandled exception, the PL/SQL does not assign values to the actual parameters.