更多"class A {   pub"的相关试题:
[单项选择] 现有代码片段: String s="123"; String sl=S+456; 请问sl的结果是哪项?()
A. 123456
B. 579
C. 编译错误
D. 运行时抛出异常
[单项选择] class Sock2 { String color; public boolean equals(Object o) { return color.equals(((Sock2)o).color); } } class TestSocks { public static void main(String [] args) { Sock2 s1 = new Sock2(); s1.color = "blue"; Sock2 s2 = new Sock2(); s2.color = "blue"; if (s1.equals(s2)) System.out.print("equals "); if (s1 == s2) System.out.print("== "); } } 结果为:()
A. ==
B. equals
C. equals ==
D. 无结果输出
[单项选择] Given: 11. String test = "This is a test"; 12. String[] tokens = test.split("/s"); 13. System.out.println(tokens.length); What is the result?()
A. An exception is thrown at runtime.
B. 1
C. 4
D. Compilation fails.
E. 0
[单项选择] public String makinStrings() { String s = “Fred”; s = s + “47”; s = s.substring(2, 5); s = s.toUpperCase(); return s.toString(); } How many String objects will be created when this method is invoked?()
A. 1
B. 2
C. 3
D. 4
E. 5
F. 6
[单项选择] public static void test(String str) { int check = 4; if (check = str.length()) { System.out.print(str.charAt(check -= 1) +“, “); } else { System.out.print(str.charAt(0) + “, “); } } and the invocation: test(”four”); test(”tee”); test(”to”); What is the result?()
A. r, t, t,
B. r, e, o,
C. Compilation fails.
D. An exception is thrown at runtime.
[单项选择] int index = 1; String [] test = new String[3]; String foo = test[index]; What is the result?()
A. Foo has the value “”
B. Foo has the value null
C. An exception is thrown
D. The code will not compile
[多项选择] class Sock { String size; String color; public boolean equals(Object o) { Sock s = (Sock) o; return color.equals(s.color); } // insert code here } 哪两个满足 hashCode 的约定?()
A. public int hashCode() { return 343; }
B. public int hashCode() { return size.hashCode (); }
C. public int hashCode() { return color.hashCode (); }
D. public int hashCode() { return (int) (Math.random() * 1000);
[单项选择] class Guy { String greet() { return "hi "; } } class Cowboy extends Guy { String greet() { return "howdy "; } } class Wrangler extends Cowboy { String greet() { return "ouch! "; } } class Greetings2 { public static void main(String [] args) { Guy g = new Wrangler(); Guy g2 = new Cowboy(); Wrangler w2 = new Wrangler(); System.out.print(g.greet()+g2.greet()+w2.greet()); } } 结果是什么?()
A. hi hi ouch!
B. hi howdy ouch!
C. ouch! howdy ouch!
D. 编译失败
[多项选择] String s= "hello"; String t = "hello"; char c[] = {’h’,’e’,’l’,’l’,’o’} ; Which return true?()
A. s.equals(t);
B. t.equals(c);
C. s==t;
D. t.equals(new String("hello"));
E. t==c;
[单项选择] 现有: class Guy {String greet() {return "hi"; } } class Cowboy extends Guy ( String greet() ( return "howdy ¨; ) ) class Surfer extends Guy (String greet() (return "dude! ";)) class Greetings { public static void main (String [] args) { Guy [] guys = ( new Guy(), new Cowboy(), new Surfer() ); for (Guy g: guys) System.out.print (g.greet()}; } } 结果为:()
A. hi howdy dude!
B. 运行时异常被抛出。
C. 第7行出现一个错误,编译失败。
D. 第8行出现一个错误,编译失败。
[多项选择] Given: String value = getServletContext().getInitParameter("foo"); in an HttpServlet and a web applicationdeployment descriptor that contains:
foo frodo Which two are true?()
A. The foo initialization parameter CANNOT be set programmatically.
B. Compilation fails because getInitParameter returns type Object.
C. The foo initialization parameter is NOT a servlet initialization parameter.
D. Compilation fails because ServletContext does NOT have a getInitParameter method.
E. The foo parameter must be defined within the
element of the deployment descriptor.
[单项选择] 11. String test = “Test A. Test B. Test C.”; 12. // insert code here 13. String[] result = test.split(regex); Which regular expression inserted at line 12 will correctly split test into “Test A,” “Test B,” and “Test C”?()
A. String regex = “”;
B. String regex = “ “;
C. String regex = “.*“.
D. String regex = “//s”
E. String regex = “//.//s*”;
F. String regex = “//w[ /.] +“;
[单项选择] 11. String test = “This is a test”; 12. String[] tokens = test.split(”/s”); 13. System.out.println(tokens.length); What is the result?()
A. 0
B. 1
C. 4
D. Compilation fails.
E. An exception is thrown at runtime.
[多项选择] 35. String #name = “Jane Doe”; 36. int$age=24; 37. Double_height = 123.5; 38. double~temp = 37.5; Which two are true?()
A. Line 35 will not compile.
B. Line 36 will not compile.
C. Line 37 will not compile.
D. Line 38 will not compile.
[单项选择] Given: 11.String test = "Test A. Test B. Test C."; 12.// insert code here 13.String[] result = test.split(regex); Which regular expression, inserted at line 12,correctly splits test into "Test A","Test B",and "Test C"?()
A. String regex = "";
B. String regex = " ";
C. String regex = ".*";
D. String regex = "//s";
E. String regex = "//.//s*";
[多项选择] 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?()
A. Line 35 will not compile.
B. Line 36 will not compile.
C. Line 37 will not compile.
D. Line 38 will not compile.
[单项选择] Given: 11.String test = "This is a test"; 12.String[] tokens = test.split("/s"); 13.System.out.println(tokens.length); What is the result?()
A. 0
B. 1
C. 4
D. Compilation fails.
[单项选择] 现有: String s="write a line to a file"; w.print(s+"/n"); 哪一个是对的?()
A. w即可以是PrintWriter类型,也可以足BufferedWriter类型。
B. w即不可以是PrintWriter类型,也不可以足BufferedWriter类型。
C. w可以是BufferedWriter类型,但不可以是PrintWriter类型。
D. w以是PrintWriter类型,但不可以是BufferedWriter类型。
[填空题] 3. string foo = “ABCDE”; 4. foo.substring(3); 5. foo.concat(“XYZ”); 6. Type the value of foo at line 6.()
[填空题] 5. String foo = “base”; 6. foo.substring(0,3); 7. foo.concat(“ket”) 8. Type the value of foo at line 8.()