discussion1 quiz. q1 which of the following are invalid java identifiers (variable names)? a) if b)...
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Q1
Which of the following are invalid Java identifiers (variable names)?
a) ifb) n4m3c) Javad) 12345e) DEFAULT_VALUEf) bad-choiceg) 1two3h) first namei) last.name
A1
Which of the following are invalid Java identifiers (variable names)?
a) ifb) n4m3c) Javad) 12345e) DEFAULT_VALUEf) bad-choiceg) 1two3h) first namei) last.name
Q2
Which of these identifiers violate the naming convention for object names?
a) R2D2
b) isthisokay?
c) Java
d) 3CPO
e) ThisIsReallyOkay
f) Java
g) anotherbadone
A2
Which of these identifiers violate the naming convention for object names?
a) R2D2
b) isthisokay?
c) Java
d) 3CPO
e) ThisIsReallyOkay
f) Java
g) anotherbadone
Q3
What is the output of the following statements
a) System.out.println( (a++)++ );
b) System.out.println( 2.5 == 5 / 2 );
c) System.out.println( 2.0 + 3/2 );
d) System.out.println( 5 % 3);
e) System.out.println(5 + 4/2.0);
f) float f = 1.1;System.out.println(f – 0.1);
g) int a = 10; System.out.println(a = 11);
A3
What is the output of the following statements
a) System.out.println( (a++)++ ); //error!
b) System.out.println( 2.5 == 5 / 2 ); //false
c) System.out.println( 2.0 + 3/2 ); //3.0
d) System.out.println( 5 % 3); //2
e) System.out.println(5 + 4/2.0); // 7.0
f) float f = 1.1;System.out.println(f – 0.1); //error!
g) int a = 10; System.out.println(a = 11); //11
Q4
What is the result?boolean b1 = true;Boolean b2 = false;System.out.println(b1 || b2 = true);System.out.println(b1);System.out.println(b2);
A4
What is the result?boolean b1 = true;Boolean b2 = false;System.out.println(b1 || b2 = true);//b1 || b2 is evaluated first before =System.out.println(b1);System.out.println(b2);
Q5
What is the result?boolean b1 = true;Boolean b2 = false;System.out.println(b1 || (b2 = true));System.out.println(b1);System.out.println(b2);
A5
What is the result?boolean b1 = true;Boolean b2 = false;System.out.println(b1 || (b2 = true));
//trueSystem.out.println(b1); //trueSystem.out.println(b2); //false
Q6
What is the result?boolean b1 = true;Boolean b2 = false;System.out.println(b1 && (b2 = true));System.out.println(b1);System.out.println(b2);
A6
What is the result?boolean b1 = true;Boolean b2 = false;System.out.println(b1 && (b2 = true)); //trueSystem.out.println(b1); //trueSystem.out.println(b2); //true
Q7
What’s the output?String s1 = new String("John");
String s2 = new String("John");
if (s1 == s2)
System.out.println("s1 == s2 is true");
else
System.out.println("s1 == s2 is false");
A7
What’s the output?String s1 = new String("John");
String s2 = new String("John");
if (s1 == s2)
System.out.println("s1 == s2 is true");
else
System.out.println("s1 == s2 is false");
// s1 == s2 is false
A8
Is there any problem with this?int a = 10;double b = 1.0;a = a + b; //type errorSystem.out.println(a);