多项选择题
Which of these statements concerning the collection interfaces are true？（）
A.Set extends Collection.
B.All methods defined in Set are also defined in Collection.
C.List extends Collection.
D.All methods defined in List are also defined in Collection.
E.Map extends Collection.
相关考题
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单项选择题
Which code fragments will succeed in printing the last argument given on the command line to the standard output， and exit gracefully with no output if no arguments are given？（） CODE FRAGMENT a： public static void main（String args[]） { if （args.length != 0） System.out.println（args[args.length-1]）； } CODE FRAGMENT b： public static void main（String args[]） { try { System.out.println（args[args.length]）； } catch （ArrayIndexOutOfBoundsException e） {} } CODE FRAGMENT c： public static void main（String args[]） { int ix = args.length； String last = args[ix]； if （ix != 0） System.out.println（last）； } CODE FRAGMENT d： public static void main（String args[]） { int ix = args.length-1； if （ix > 0） System.out.println（args[ix]）； } CODE FRAGMENT e： public static void main（String args[]） { try { System.out.println（args[args.length-1]）； }catch （NullPointerException e） {} }
A.Code fragment a.
B.Code fragment b.
C.Code fragment c.
D.Code fragment d.
E.Code fragment e. -
多项选择题
Whichstatementsdescribeguaranteedbehaviorofthegarbagecollectionandfinalizationmechanisms？（）
A.Objects are deleted when they can no longer be accessed through any reference.
B.The finalize（） method will eventually be called on every object.
C.The finalize（） method will never be called more than once on an object.
D.An object will not be garbage collected as long as it is possible for an active part of the program to access it through a reference.
E.The garbage collector will use a mark and sweep algorithm. -
多项选择题
Whichstatementsconcerningthevalueofamembervariablearetrue，whennoexplicitassignmentshavebeenmade？（）
A.The value of an int is undetermined.
B.The value of all numeric types is zero.
C.The compiler may issue an error if the variable is used before it is initialized.
D.The value of a String variable is "" （empty string）.
E.The value of all object variables is null.
