huashui questions

• When I new a Hashtable, why the put method is invocated?
• what will translate function do if I want to change some chars to nothing?
• What does "-" mean in this linux command?
• why is static inner class singleton thread safe [duplicate]
• What does "T is a top-level class, and an assert statement lexically nested within T is executed." mean?
• In what situations is the CopyOnWriteArrayList suitable? [duplicate]

huashui answers