Chapter 2 Operators and Statements

Question 1

What happens with byte, short, char data types when they are used with Java binary aritmetic operators ?

Answer 1

Smaller data types, namely byte, short, and char, are first promoted to int any time they’re used with a Java binary arithmetic operator, even if neither of the operands is int.

Question 2

What types of operators are available in Java ?

Answer 2

Three types of operators are available in Java: unary, binary, and ternary. These types of operators can be applied to one, two, or three operands, respectively.

Question 3

What will happen while applying operators to data types, when two values have different data types?

Answer 3

If two values have different data types, Java will automatically promote one of the values to the larger of the two data types.

Question 4

What is the data type of the result after applying operators to different data types?

Answer 4

After all promotion has occurred and the operands have the same data type, the resulting value will have the same data type as its promoted operands.

Question 5

When casting primitives values is required ?

Answer 5

Casting primitives is required any time you are going from a larger numerical data type to a smaller numerical data type, or converting from a floating-point number to an integral value.

int x = (int)1.0;

short y = (short)1921222;

int z = (int)9l;

long t = 192301398193810323L;

Question 6

What will be printed:

long x = 5;

long y = (x=3);

System.out.println(x);

System.out.println(y);

Answer 6

Console output:

3
3

Question 7

What is the result of:

short x = 10;

short y = 3;

short z = x * y;

Answer 7

Does not compile

(promoted to int when applying any arithmetic operator, with the resulting value being of type int)

Question 8

What is the difference between &&,|| and &,| operators ?

Answer 8

The short-circuit operators (&&, ||) are nearly identical to the logical operators (&, |) except that the right-hand side of the expression may never be evaluated if the final result can be determined by the left-hand side of the expression.

Question 9

What will be the output:

int y = 1;

int z = 1;

final int x = y<10 ? y++ : z++;

System.out.println(y+”,”+z);

Answer 9

Console output:

2,1
As of Java 7, only one of the right-hand expressions of the ternary operator will be evaluated at runtime. In a manner similar to the short-circuit operators, if one of the two righthand expressions in a ternary operator performs a side effect, then it may not be applied at runtime.

Question 10

What data types are supported by switch statements ?

Answer 10

int and Integer, byte and Byte, short and Short, char and Character, String, enum values

Question 11

What will be the output of:

for ( ; ; ) { System.out.println(“Hello World”); }

Answer 11

The code creates an infine loop.

Question 12

What is label ?

Answer 12

A label is an optional pointer to the head of a statement that allows the application flow to jump to it or break from it. It is a single word that is proceeded by a colon (:)
..OUTER_LOOP: for(int[] mySimpleArray : myComplexArray).. they are commonly expressed in uppercase, with underscores between words, to distinguish them from regular variables.