Scjp 6.0 _ Java _ Level 1
歡迎來挑戰 SCJP 6. 0_JAVA_ level 1
- 1.Given: public class TestString1 { public static void main(String[] args) { String str = "420"; str += 42; System.out.print(str); } } What is the output?
- A.
42
- B.
420
- C.
462
- D.
42042
- E.
Compilation fails.
- F.
An exception is thrown at runtime.
- 2.Given: 35. String #name = "Jane Doe"; 36. int $age = 24; 37. Double _height = 123.5; 38. double ~temp = 37.5; Which two statements are true? (Choose two.)
- A.
Line 35 will not compile.
- B.
Line 36 will not compile.
- C.
Line 37 will not compile.
- D.
Line 38 will not compile.
- 3.Given: public class Test { public static void main(String[] args) { int x = 5; boolean b1 = true; boolean b2 = false; if ((x == 4) && !b2) System.out.print("1 "); System.out.print("2 "); if ((b2 = true) && b1) System.out.print("3 "); } } What is the result?
- A.
2
- B.
3
- C.
12
- D.
23
- E.
123
- F.
Compilation fails.
- G.
An exception is thrown at runtime.
- 4.Given: public void go() { String o = ""; z: for (int x = 0; x < 3; x++) { for (int y = 0; y < 2; y++) { if (x == 1)break; if (x == 2 && y == 1)break z; o = o + x + y; } } System.out.println(o); } What is the result when the go() method is invoked?
- A.
00
- B.
0001
- C.
000120
- D.
00012021
- E.
Compilation fails.
- F.
An exception is thrown at runtime.
- 5.Given: int x = 0; int y = 10; while (x < 5) { y--; ++x; } ; System.out.print(x + "," + y); What is the result?
- A.
5,6
- B.
5,5
- C.
6,5
- D.
6,6
- 6.Given: public class Breaker2 { static String o = ""; public static void main(String[] args) { z: for (int x = 2; x < 7; x++) { if (x == 3) continue; if (x == 5) break z; o = o + x; } System.out.println(o); } } What is the result?
- A.
2
- B.
24
- C.
234
- D.
246
- E.
2346
- F.
Compilation fails.
- 7.Given: String[] elements = {"for", "tea", "too"}; String first = (elements.length>0) ? elements[0] : null; What is the result?
- A.
Compilation fails.
- B.
An exception is thrown at runtime.
- C.
The variable first is set to null.
- D.
The variable first is set to elements[0].
- 8.Given: class Alligator { public static void main(String[] args) { int[] x[] = { { 1, 2 }, { 3, 4, 5 }, { 6, 7, 8, 9 } }; int y[][] = x; System.out.print(y[2][1]); } } What is the result?
- A.
2
- B.
3
- C.
4
- D.
6
- E.
7
- F.
Compilation fails.
- 9.Given: public class Barn { public static void main(String[] args) { new Barn.go("hi", 1); new Barn.go("hi", "world", 2); } public void go(String... y, int x) { System.out.print(y[y.length - 1] + " "); } } What is the result?
- A.
Hi hi
- B.
Hi world
- C.
World world
- D.
Compilation fails.
- E.
An exception is thrown at runtime.
- 10.Given: 1. class Super{ 2. private int a; 3. protected Super(int a){this.a = a;} 4. } ... 11. class Sub extends Super{ 12. public Sub(int a){super(a);} 13. public Sub(){this.a = 5;} 14. } Which two, independently, will allow Sub to compile? (Choose two.)
- A.
Change line 2 to: public int a;
- B.
Change line 2 to: protected int a;
- C.
Change line 13 to: public Sub(){this(5);}
- D.
Change line 13 to: public Sub(){super(5);}
- E.
Change line 13 to: public Sub(){super(a);}
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