1. public Object m() { Object o = new Float(3.14F); Object [] oa = new Object[l]; oa[0] = o; / Line 5 / o = null; / Line 6 / oa[0] = null; / Line 7 / return o; / Line 8 / } When is the Float object, created in line 3, eligible for garbage collection?
2. class X2 { public X2 x; public static void main(String [] args) { X2 x2 = new X2(); / Line 6 / X2 x3 = new X2(); / Line 7 / x2.x = x3; x3.x = x2; x2 = new X2(); x3 = x2; / Line 11 / doComplexStuff(); } } after line 11 runs, how many objects are eligible for garbage collection?
3. What allows the programmer to destroy an object x?
4. void start() { A a = new A(); B b = new B(); a.s(b); b = null; / Line 5 / a = null; / Line 6 / System.out.println("start completed"); / Line 7 / } When is the B object, created in line 3, eligible for garbage collection?
5. class HappyGarbage01 { public static void main(String args[]) { HappyGarbage01 h = new HappyGarbage01(); h.methodA(); / Line 6 / } Object methodA() { Object obj1 = new Object(); Object [] obj2 = new Object[1]; obj2[0] = obj1; obj1 = null; return obj2[0]; } } Where will be the most chance of the garbage collector being invoked?
6. class Bar { } class Test { Bar doBar() { Bar b = new Bar(); / Line 6 / return b; / Line 7 / } public static void main (String args[]) { Test t = new Test(); / Line 11 / Bar newBar = t.doBar(); / Line 12 / System.out.println("newBar"); newBar = new Bar(); / Line 14 / System.out.println("finishing"); / Line 15 / } } At what point is the Bar object, created on line 6, eligible for garbage collection?
7. class Test { private Demo d; void start() { d = new Demo(); this.takeDemo(d); / Line 7 / } / Line 8 / void takeDemo(Demo demo) { demo = null; demo = new Demo(); } } When is the Demo object eligible for garbage collection?
8. public class X { public static void main(String [] args) { X x = new X(); X x2 = m1(x); / Line 6 / X x4 = new X(); x2 = x4; / Line 8 / doComplexStuff(); } static X m1(X mx) { mx = new X(); return mx; } } After line 8 runs. how many objects are eligible for garbage collection?