QBasic Programs – Conditional Statements & Loops

<<< Questions

1. IF Statement (Simple IF)

1. Positive Number


CLS
INPUT "Enter a number"; A
IF A > 0 THEN PRINT "Positive Number"
END

Output


Enter a number? 5
Positive Number

2. Voting Eligibility


CLS
INPUT "Enter age"; A
IF A >= 18 THEN PRINT "Eligible to Vote"
END

Output


Enter age? 20
Eligible to Vote

3. Even Number


CLS
INPUT "Enter a number"; A
IF A MOD 2 = 0 THEN PRINT "Even Number"
END

Output


Enter a number? 8
Even Number

4. Pass


CLS
INPUT "Enter marks"; M
IF M >= 40 THEN PRINT "Pass"
END

Output


Enter marks? 55
Pass

5. Uppercase Letter


CLS
INPUT "Enter a character"; C$
IF C$ >= "A" AND C$ <= "Z" THEN PRINT "Uppercase Letter"
END

Output


Enter a character? A
Uppercase Letter

2. IF–ELSE Statement

1. Even or Odd


CLS
INPUT "Enter a number"; A
IF A MOD 2 = 0 THEN
PRINT "Even"
ELSE
PRINT "Odd"
END IF
END

Output


Enter a number? 7
Odd

2. Greatest of Two


CLS
INPUT "Enter two numbers"; A, B
IF A > B THEN
PRINT A
ELSE
PRINT B
END IF
END

Output


Enter two numbers? 9 4
9

3. Taxable Salary


CLS
INPUT "Enter salary"; S
IF S > 50000 THEN
PRINT "Taxable"
ELSE
PRINT "Not Taxable"
END IF
END

Output


Enter salary? 30000
Not Taxable

4. Hot or Cold


CLS
INPUT "Enter temperature"; T
IF T > 30 THEN
PRINT "Hot Day"
ELSE
PRINT "Cold Day"
END IF
END

Output


Enter temperature? 35
Hot Day

5. Positive or Negative


CLS
INPUT "Enter number"; N
IF N >= 0 THEN
PRINT "Positive"
ELSE
PRINT "Negative"
END IF
END

Output


Enter number? -5
Negative

3. IF–ELSEIF Ladder

1. Division


CLS
INPUT "Enter marks"; M
IF M >= 80 THEN 
PRINT "Distinction"
ELSEIF M >= 60 THEN 
PRINT "First Division"
ELSEIF M >= 45 THEN 
PRINT "Second Division"
ELSEIF M >= 32 THEN 
PRINT "Third Division"
ELSE 
PRINT "Fail"
END IF
END

Output


Enter marks? 70
First Division

2. Positive, Negative, Zero


CLS
INPUT "Enter number"; N
IF N > 0 THEN 
PRINT "Positive"
ELSEIF N < 0 THEN 
PRINT "Negative"
ELSE 
PRINT "Zero"
END IF
END

Output


Enter number? 0
Zero

3. Age Group


CLS
INPUT "Enter age"; A
IF A < 13 THEN 
PRINT "Child"
ELSEIF A < 20 THEN 
PRINT "Teenager"
ELSEIF A < 60 THEN 
PRINT "Adult"
ELSE 
PRINT "Senior Citizen"
END IF
END

Output


Enter age? 25
Adult

4. Vowel or Consonant


CLS
INPUT "Enter character"; C$
IF C$="A" OR C$="E" OR C$="I" OR C$="O" OR C$="U" THEN
PRINT "Vowel"
ELSEIF C$>="A" AND C$<="Z" THEN
PRINT "Consonant"
ELSE
PRINT "Invalid"
END IF
END

Output


Enter character? B
Consonant

5. Electricity Bill


CLS
INPUT "Enter units"; U
IF U<=20 THEN B=U*3
ELSEIF U<=50 THEN 
B=20*3+(U-20)*5
ELSE 
B=20*3+30*5+(U-50)*7
END IF
PRINT "Bill = "; B
END

Output


Enter units? 60
Bill = 280

4. FOR…NEXT Loop

1. 1 to 10


CLS
FOR I = 1 TO 10
PRINT I
NEXT I
END

Output


1
2
3
4
5
6
7
8
9
10

2. Multiplication Table


CLS
INPUT "Enter number"; N
FOR I = 1 TO 10
PRINT N; " x "; I; " = "; N * I
NEXT I
END

Output


Enter number? 5
5 x 1 = 5
5 x 2 = 10
5 x 3 = 15
5 x 4 = 20
5 x 5 = 25
5 x 6 = 30
5 x 7 = 35
5 x 8 = 40
5 x 9 = 45
5 x 10 = 50

3. Sum of 100


CLS
S = 0
FOR I = 1 TO 100
S = S + I
NEXT I
PRINT S
END

Output


5050

4. Even Numbers (2 to 50)


CLS
FOR I = 2 TO 50 STEP 2
PRINT I
NEXT I
END

Output


2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50

5. Factorial


CLS
INPUT "Enter number"; N
F = 1
FOR I = 1 TO N
F = F * I
NEXT I
PRINT F
END

Output


Enter number? 5
120

5. DO WHILE Loop

1. 1 to 10


CLS
I = 1
DO WHILE I <= 10
PRINT I
I = I + 1
LOOP
END

Output


1
2
3
4
5
6
7
8
9
10

2. Odd Numbers (1 to 50)


CLS
I = 1
DO WHILE I <= 50
PRINT I
I = I + 2
LOOP
END

Output


1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49

3. Sum of Digits


CLS
INPUT "Enter number"; N
S = 0
DO WHILE N > 0
S = S + N MOD 10
N = N \ 10
LOOP
PRINT S
END

Output


Enter number? 1234
Sum = 10

4. Reverse Number


CLS
INPUT "Enter number"; N
R = 0
DO WHILE N > 0
R = R * 10 + N MOD 10
N = N \ 10
LOOP
PRINT R
END

Output


Enter number? 456
654

5. Until 0


CLS
DO
INPUT "Enter number"; N
PRINT N
LOOP WHILE N <> 0
END

Output


Enter number? 5
5
Enter number? 3
3
Enter number? 0
0

6. WHILE…WEND Loop

1. 10 to 1


CLS
I = 10
WHILE I >= 1
PRINT I
I = I - 1
WEND
END

Output


10
9
8
7
6
5
4
3
2
1

2. Sum up to N


CLS
INPUT "Enter N"; N
I = 1
S = 0
WHILE I <= N
S = S + I
I = I + 1
WEND
PRINT S
END

Output


Enter N? 10
55

3. Count Digits


CLS
INPUT "Enter number"; N
C = 0
WHILE N > 0
C = C + 1
N = N \ 10
WEND
PRINT C
END

Output


Enter number? 12345
5

4. Palindrome


CLS
INPUT "Enter number"; N
T = N
R = 0
WHILE N > 0
R = R * 10 + N MOD 10
N = N \ 10
WEND
IF R = T THEN
PRINT "Palindrome"
ELSE
PRINT "Not Palindrome"
END IF
END

Output


Enter number? 121
Palindrome

5. Sum of Even Numbers


CLS
I = 2
S = 0
WHILE I <= 100
S = S + I
I = I + 2
WEND
PRINT S
END

Output


2550

7. Nested FOR…NEXT Loop

1. Star Pattern


CLS
FOR I = 1 TO 4
FOR J = 1 TO I
PRINT "* ";
NEXT J
PRINT
NEXT I
END

Output


*
* *
* * *
* * * *

2. Matrix (3 × 3)


CLS
K = 1
FOR I = 1 TO 3
FOR J = 1 TO 3
PRINT K; " ";
K = K + 1
NEXT J
PRINT
NEXT I
END

Output


1 2 3
4 5 6
7 8 9

3. Tables from 1 to 2


CLS
FOR I = 1 TO 2        ' Loop for tables 1 to 2
    FOR J = 1 TO 10   ' Loop for multiplication 1 to 10
        PRINT I; " x "; J; " = "; I * J
    NEXT J
    PRINT              ' Blank line after each table
NEXT I
END

Output


1 x 1 = 1
1 x 2 = 2
1 x 3 = 3
1 x 4 = 4
1 x 5 = 5
1 x 6 = 6
1 x 7 = 7
1 x 8 = 8
1 x 9 = 9
1 x 10 = 10

2 x 1 = 2
2 x 2 = 4
2 x 3 = 6
2 x 4 = 8
2 x 5 = 10
2 x 6 = 12
2 x 7 = 14
2 x 8 = 16
2 x 9 = 18
2 x 10 = 20

4. Number Pyramid


CLS
FOR I = 1 TO 4
FOR J = 1 TO I
PRINT J; " ";
NEXT J
PRINT
NEXT I
END

Output


1
1 2
1 2 3
1 2 3 4

5. Student Total


CLS
FOR I = 1 TO 5
T = 0
FOR J = 1 TO 3
INPUT M
T = T + M
NEXT J
PRINT "Total = "; T
NEXT I
END

Output


Enter marks? 50
Enter marks? 60
Enter marks? 70
Total = 180