Ch 16 Expressions and Operators

 1. Fill in the blanks:

a. Different types of expressions supported by QBASIC are logical,

………. and …….

b. Different types of operators of QBASIC are ……., ........, .... and ....

c. 'OR' is a ................. operator.

d. '<>' is a........................operator.

e. '\, * are............. operators.

f. T$="RAM"+"SHYAM" is an example of……..

g.7>4 AND 7> 9 is an example of…....operation.

h. 5*5 is an example of.............operation.

i. PRINT 7>4 AND 8>3 produces output……

a. arithmetic and string b. Arithmetic, Relational, Logical and string c. logical d. relational e. arithmetic f. string operator g. relational h. arithemtic i. minus one (-1) i.e. TRUE

2. Write 'T' for the correct and 'F' for the false statements:

a. Combination of variables, operators and data is called an expression.

b. "+" symbol can be used for arithmetic as well as string operations.

c.A relational expression returns logical values.

d. "AND" operator returns "O", if all the given conditions are true.

e. "OR" operator returns "-1", if all the given conditions are true.

f. "NOT" operator reverses the result of a logical expression.

g. Mathematical operators can be disguised.

a. True b. True c. True d. False e. True f. True g. False

3. Evaluate the following expressions:

Expressions	Outputs
PRINT (5+7) - ( 4 + 2 )	6
PRINT ( 4 +2 ) ^ 2 / (2+2)	9
PRINT 3+2\2 +1	5
PRINT 3^2 MOD 3+1	1
PRINT (3+3) > 3 AND (9+1) > 12 AND 34 > 30	False(0)
PRINT 3 MOD 2 = 1 OR 3 ^ 2 = 6 OR (8 * 2 ) = 30	True(-1)
PRINT “AB” + “plus” + “XY”	ABplusxy

4.Answer the following questions:

a. Define an expression. Give an example.

A string or numeric constant, a variable or a combination of constants and variables with operators is said to be expression. Example: Print 7*6+5

b. What are operators? Name the operators supported by QBASIC.

The symbols, which are used for mathematical calculations, logical and string operations are called operators. The operators supported by QBASIC are as follows:

- Arithmetic Operator

- Relational Operator

- Logical Operator

-String Operator

c. What is arithmetic expression? Give an example.

An expression, which contains values , variables and operators that return a single numeric value after operations, is called arithmetic expression. Example: Print 7*6+5

d. What is logical expression? Give an example.

A logical expression contains values and operations which are evaluated by QBASIC and returns one of two logical values (true or false), which are also called Boolean values. Example : Print 6>5

e. What are arithmetic operators? Write them in hierarchy.

Arithmetic or Mathematical operators are symbols, which are used for mathematical operations.

Arithmetic Operators	Symbol	Order of Priority
Expressions inside the brackets	( )	First
Exponentiation	^	Second
Negation (Minus sign before value)	-	Third
Multiplication and Division	* , /	Fourth
Integer Division	\	Fifth
Modulo Arithmetic	MOD	Sixth
Addition & Subtraction	+ , -	Seventh

f. What is the use of logical operators? Explain with examples.

Logical operator is used to combine two or more logical or relational expressions and return a single “ True ” or “ False ” value. QBASIC evaluates the expressions and return “ -1 ” for a true and “ 0 ” for a false result.

g. Write truth table of "AND","OR" and "NOT"operators.

Truth Table of AND Operator
Condition	Operator(AND)	Condition	Result
FALSE (0)	AND	FALSE (0)	FALSE (0)
FALSE (0)	AND	TRUE (-1)	FALSE (0)
TRUE (-1)	AND	FALSE (0)	FALSE (0)
TRUE (-1)	AND	TRUE (-1)	TRUE (-1)

Truth Table of OR Operator
Condition	Operator(OR)	Condition	Result
FALSE (0)	OR	FALSE (0)	FALSE (0)
FALSE (0)	OR	TRUE (-1)	TRUE (-1)
TRUE (-1)	OR	FALSE (0)	TRUE (-1)
TRUE (-1)	OR	TRUE (-1)	TRUE (-1)

Truth Table of NOT Operator
Condition	Result
FALSE (0)	TRUE (-1)
TRUE (-1)	FALSE (0)

h. What is string concatenation? Give an example.

The act of combining strings is called string concatenation. For Example: PRINT “ AB ” + “ plus ” + “ XY ” After String Concatenation: ABplusXY