1. Fill in the blanks:
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. State true or false:
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.
Answer: 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.
Answer: 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.
Answer: 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.
Answer: 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.
Answer: 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.
Answer: 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.
Answer: The act of combining strings is called string concatenation.
For Example: PRINT “ AB ” + “ plus ” + “ XY ”
After String Concatenation: ABplusXY
