Transcript EVS-java
JAVA Revision Lecture
Electronic Voting System
Marina De Vos
0a. What are the languages used in
this unit?
1. C and Java
2. Python and Java
3. Perl and
VisualBasic
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0b. Ada Lovelace was the first …
1. female
programmer
2. the wife of the first
programmer
3. programmer
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1. Which one of the sentences is
true considering the following lines
of code:
String country = "England";
Town bath = new Town(country);
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2.
3.
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
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2. What is the value returned while
calling the method refundBalance(10)?
public int refundBalance(int nb){
balance=100;
return balance;
balance=0;
}
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2.
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4.
80%
0
10
100
Same value as before
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3. Which one of the following
sentences is correct?
1.
2.
3.
4.
5.
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
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defining class
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4. Which values have the variables a
and b after the execution of the
following lines of code:
int a=3;
int b=5;
int c=a++;
int d=--b;
if ((a+1)==d){
c++;
b--;
}
if (c!=b){
a++;
}
else {
b++;
}
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2.
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4.
5.
a=3; b=4;
a=4; b=4;
a=3; b=5;
a=5; b=4;
a=4; b=5;
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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;
}
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1. 27
2. 25
3. 45
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6. Why do you need to add 'throws'
to a method signature...
1.
2.
3.
4.
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
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7. A 'try' must be followed by one
or more 'catch' blocks.
1. True
2. False
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8. What happens to the object being
created when an exception is
thrown from a constructor?
1. null is returned
and the partial
object is garbage
collected
2. a partial object is
created
3. null is returned
4. the object is fully
created
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9. Code that is well designed is:
1. tighly coupled and
not cohesive
2. loosly coupled
and not cohesive
3. tighly coupled and
highly cohesive
4. loosly coupled
and highly
cohesive
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10. Java is a …
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2.
3.
4.
weakly and statically
typed language
weakly and dynamically
typed language
strongly and statically
typed language
strongly and
dynamically typed
language
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11. The lifetime and scope of a
variable a is defined by the
enclosing {} braces.
1. True
2. False
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12. Object diagrams can present
both a static and dynamic view of a
program.
1. True
2. False
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13. To create a new primitive type
in Java, you can...
1. copy an existing
primitive type
definition and edit
2. ...you can't!
3. use the new
primitive keyword
4. not necessary - all
new types are
primitive types
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14. A & B is the same as B & A for
any boolean expression in Java.
1. True
2. False
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15. In Java, it is not possible to
have more than one method with
the same name.
1. True
2. False
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16. Consider the following code
snippet: What will the output be?
HashMap<String,String> map = new HashMap<String,String>();
map.put("key1","arr");
map.put("key1","matey");
System.out.println(map.get("key1"));
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4.
arr
Nothing, it will generate
an error.
arr matey
matey
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17. Which of the following
statements is incorrect?
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2.
3.
4.
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
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18 Newly declared methods can hide,
implement, or override methods declared in
a superclass or superinterface.
1. True
2. False
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19 It is possible to have a variable with a
static type corresponding to an abstract
class
1. True
2. False
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20 To simulate multiple inheritance
you use:
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2.
3.
4.
nested classes
abstract classes
interfaces
inherited classes
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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
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5.
Strongly Agree
Agree
Neutral
Disagree
Strongly Disagree
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Java EVS vs Python Quiz
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2.
3.
4.
evs
Quiz
I liked both
I liked neither
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EVS: Although good for general
feed-back how we are doing, it’s
not so good for passing course
material on.
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2.
3.
4.
5.
Strongly Agree
Agree
Neutral
Disagree
Strongly Disagree
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