Question 1

Question 1We have two variables x and y. Write Java statements to calculate the result of division of y by x and calculate the remainder of the division.

Accepted Answer

int quotient = y / x;
int remainder = y % x;

Question 2

Question 2Assign the value of pi (i.e., 3.142) to a variable with requisite data type.

Accepted Answer

float pi = 3.142f;

Question 3

Question 3What are logical operators? Give an example of each.

Accepted Answer

Logical operators operate only on boolean operands and are used to construct complex decision-making expressions. Some of the logical operators are given below:OperatorSymbolLogical AND&&Logical OR||Logical NOT!

Question 4

Question 4What is an assignment operator? Give an example.

Accepted Answer

Assignment operator is used to assign the value of an expression to a variable. It has the following syntax:variable = expression;For example,totalMarks = 780;The above statement assigns the value of 780 to the variable totalMarks. Any previous value stored in totalMarks variable is overwritten by this new value.

Question 5

Question 5Explain the shorthand assignment operator with an example.

Accepted Answer

Java provides shorthand assignment operators for all the arithmetic binary operators. Shorthand assignment operators follow the below syntax:variable = variable operation expression;Taking the example of shorthand addition operator, the expression x = x + 3 can be rewritten as x += 3;

Question 6

Question 6What is the purpose of the new operator?

Accepted Answer

The new operator is used to allocate memory for the object.

Question 7

Question 7What is the use and syntax of a ternary operator?

Accepted Answer

Ternary operator is used to check if a condition is true and false. Depending on whether the condition tests true or false, expression 1 or expression 2 is evaluated. Its syntax is:boolean-expression ? expression1 : expression2;

Question 8

Question 8State the difference between = and ==.

Accepted Answer

===It is the assignment operator used for assigning a value to a variable.It is the equality operator used to check if a variable is equal to another variable or literal.E.g. int a = 10; assigns 10 to variable a.E.g. if (a == 10) checks if variable a is equal to 10 or not.

Question 9

Question 9If a = 5, b = 9, calculate the value of:    a += a++ - ++b + a

Accepted Answer

a += a++ - ++b + a⇒ a = a + (a++ - ++b + a)⇒ a = 5 + (5 - 10 + 6)⇒ a = 5 + 1⇒ a = 6a++ first uses the current value of a (which is 5) in the expression and then increments it to 6. ++b first increment the current value of b to 10 and uses this incremented value in the expression.

Question 10

Question 10Distinguish between the following:a. Prefix and Postfix Increment

Accepted Answer

Prefix IncrementPostfix IncrementIt works on the principle of first increment, then use.It works on the principle of first use, then increment.It (++) is written before the operand.It (++) is written after the operand.Example:int a = 99;int b = ++a;After the execution of these two statements, both a and b will have the value of 100.Example:int a = 99;int b = a++;After the execution of these two statements, a will have the value of 100 and b will have the value of 99.b. Prefix and Postfix DecrementPrefix DecrementPostfix DecrementIt works on the principle of first decrement, then use.It works on the principle of first use, then decrement.It (--) is written before the operand.It (--) is written after the operand.Example:int a = 100;int b = --a;After the execution of these two statements, both a and b will have the value of 99.Example:int a = 100;int b = a--;After the execution of these two statements, a will have the value of 99 and b will have the value of 100.c. Unary and Binary OperatorsUnary OperatorsBinary OperatorsIt operates on a single operandIt operates on two operandsIncrement (++) and Decrement (--) operators are examples of Unary Arithmetic OperatorsMultiplication (*) and Division (/) are examples of Binary Arithmetic Operatorsd. Increment and Decrement OperatorIncrement OperatorDecrement OperatorIncrement operators increment the value of their operand by 1.Decrement operators decrement the value of their operand by 1.Increment operators are represented by ++ symbol.Decrement operators are represented by -- symbol.e. / and % operator/%It is the Division operatorIt is the Modulus operatorReturns the quotient of division operationReturns the remainder of division operationExample: int a = 5 / 2; Here a will get the value of 2 which is the quotient of this division operationExample: int b = 5 % 2; Here b will get the value of 1 which is the remainder of this division operation

Question 11

Question 11If m=5, n=2; what will be the output of m and n after execution?i. m -= n       ii. n = m + m/n

Accepted Answer

i.  m -= n⇒ m = m - n⇒ m = 5 - 2⇒ m = 3ii. n = m + m/n⇒ n = 5 + 5/2⇒ n = 5 + 2⇒ n = 7

Question 12

Question 12If x = 3, y = 7, calculate the value of:x -= x++ - ++y

Accepted Answer

x -= x++ - ++y⇒ x = x - (x++ - ++y)⇒ x = 3 - (3 - 8)⇒ x = 3 - (-5)⇒ x = 3 + 5⇒ x = 8

Question 13

Question 13What will be the output of the following if x=5?i. 5 * ++xii. 5 * x++

Accepted Answer

i.  5 * ++x⇒ 5 * 6⇒ 30ii.  5 * x++⇒ 5 * 5⇒ 25

Question 14

Question 14What is type conversion? How is an implicit type conversion different from explicit type conversion?

Accepted Answer

Type conversion is a process that converts a value of one data type to another data type.In an implicit conversion, the result of a mixed mode expression is obtained in the higher most data type of the variables without any intervention by the user. For example:int a = 10;
float b = 25.5f, c;
c = a + b;In case of explicit type conversion, the data gets converted to a type as specified by the programmer. For example:int a = 10;
double b = 25.5;
float c = (float)(a + b);

Question 15

Question 15What do you understand by type conversion?

Accepted Answer

Type conversion is a process that converts a value of one data type to another data type.

Question 16

Question 16Explain the term 'typecasting'.

Accepted Answer

The process of converting a value of one data type to another data type is called typecasting.

Question 17

Question 17What are precedence and associativity?

Accepted Answer

Precedence of operators refers to the order in which the operators are applied to the operands in an expression.Associativity of operators refers to the direction of execution of operators ("Left to Right" or "Right to Left") when operators in an expression have the same precedence.

Question 18

Question 18Evaluate the following expressions, if the values of the variables are a = 2, b = 3 and c = 3i. a - (b++) * (--c)ii. a * (++b) %c

Accepted Answer

i.  a - (b++) * (--c)⇒ 2 - 3 * 2⇒ 2 - 6⇒ -4ii. a * (++b) %c⇒ 2 * 4 % 3⇒ 8 % 3⇒ 2

Question 19

Question 19Write the Java expressions for the following:i. (a + b)2 + b

Accepted Answer

Math.pow(a+b, 2) + bii. a2 + b2a * a + b * biii. z = x3 + y3 + (xy) / 3z = Math.pow(x, 3) + Math.pow(y, 3) + x * y / 3iv. f = a2 + b2 / a2 - b2f = (a * a + b * b) / (a * a - b * b)v. z = ab + bc + ca / 3abcz = (a * b + b * c + c * a) / (3 * a * b * c)vi. 0 <= x <= 50x >= 0 && x <= 50vii. a = (0.05 - 2y3) / x - ya = (0.05 - 2 * y * y * y) / (x - y)viii. (a + b)n / √3 + bMath.pow(a+b, n) / (Math.sqrt(3) + b)ix. ax + by / ∛x + ∛y(Math.pow(a, x) + Math.pow(b, y)) / (Math.cbrt(x) + Math.cbrt(y))

Question 20

Question 20Rewrite the following statements without using shorthand operators.a. p /= qb. p -= 1c. p *= q + rd. p -= q - r

Accepted Answer

a. p = p / qb. p = p - 1c. p = p * (q + r)d. p = p - (q - r)

Operators in Java