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JAVA Revision Lecture. Electronic Voting System Marina De Vos. 0a. What are the languages used in this unit?. C and Java Python and Java Perl and VisualBasic. 0b. Ada Lovelace was the first …. female programmer the wife of the first programmer programmer.
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JAVA Revision Lecture Electronic Voting System Marina De Vos
0a. What are the languages used in this unit? • C and Java • Python and Java • Perl and VisualBasic
0b. Ada Lovelace was the first … • female programmer • the wife of the first programmer • programmer
1. Which one of the sentences is true considering the following lines of code: • the class Town contains a constructor with a String as a parameter • bath is an instance of the class England • bath is an object of type String String country = "England";Town bath = new Town(country);
2. What is the value returned while calling the method refundBalance(10)? • 0 • 10 • 100 • Same value as before public int refundBalance(int nb){ balance=100; return balance; balance=0; }
3. Which one of the following sentences is correct? • Fields represent local variables of a method • The scope of a local variable is linked to its defining method • Fields are defined inside constructors • Local variables are defined in the header of a method • A private field can be accessed from outside their defining class
4. Which values have the variables a and b after the execution of the following lines of code: • a=3; b=4; • a=4; b=4; • a=3; b=5; • a=5; b=4; • a=4; b=5; int a=3; int b=5; int c=a++; int d=--b; if ((a+1)==d){ c++; b--; } if (c!=b){ a++; } else { b++; }
5. What is the result of n? boolean pass=false; int n=0; for (int i=0; i<10; i++) { n+=i; if (pass) { i+=2; } pass = !pass; } • 27 • 25 • 45
6. Why do you need to add 'throws' to a method signature... • To Specify the exceptions thrown by a method • To specify the exceptions caught by a method • To Specify that a method overrides an exception • Both 1 and 2 are correct Choice One
7. A 'try' must be followed by one or more 'catch' blocks. • True • False
8. What happens to the object being created when an exception is thrown from a constructor? • null is returned and the partial object is garbage collected • a partial object is created • null is returned • the object is fully created
9. Code that is well designed is: • tighly coupled and not cohesive • loosly coupled and not cohesive • tighly coupled and highly cohesive • loosly coupled and highly cohesive
10. Java is a … • weakly and statically typed language • weakly and dynamically typed language • strongly and statically typed language • strongly and dynamically typed language
11. The lifetime and scope of a variable a is defined by the enclosing {} braces. • True • False
12. Object diagrams can present both a static and dynamic view of a program. • True • False
13. To create a new primitive type in Java, you can... • copy an existing primitive type definition and edit • ...you can't! • use the new primitive keyword • not necessary - all new types are primitive types
14. A & B is the same as B & A for any boolean expression in Java. • True • False
15. In Java, it is not possible to have more than one method with the same name. • True • False
16. Consider the following code snippet: What will the output be? • arr • Nothing, it will generate an error. • arr matey • matey HashMap<String,String> map = new HashMap<String,String>(); map.put("key1","arr"); map.put("key1","matey"); System.out.println(map.get("key1"));
17. Which of the following statements is incorrect? • the static type of a variable is either the same as the dynamic type or a superclass • polymorphic method calls use the dynamic type • The compiler checks the static and dynamic type of a variable • an object reference can always be type cast back to its dynamic type
18 Newly declared methods can hide, implement, or override methods declared in a superclass or superinterface. • True • False
19 It is possible to have a variable with a static type corresponding to an abstract class • True • False
20 To simulate multiple inheritance you use: • nested classes • abstract classes • interfaces • inherited classes
EVS is good fun, something different and its very good to be interactive Since we do not get much class participation, except if we want to ask questions • Strongly Agree • Agree • Neutral • Disagree • Strongly Disagree
Java EVS vs Python Quiz • evs • Quiz • I liked both • I liked neither
EVS: Although good for general feed-back how we are doing, it’s not so good for passing course material on. • Strongly Agree • Agree • Neutral • Disagree • Strongly Disagree