Perl programming

Mary PW Chin 钱碧慧博士
PhD (Wales), MSc (Surrey)
E-mail:

Perl #1

Getting started

Perl #2

Dice

❮ ❯

Synopsis

The printf function;
Variables, integers and floating-point numbers;
Arithmetic operators;
Auto-completion (TAB key) and command history (UP and DOWN arrow keys);
for loops:
Sequence of numbers;
Line and block commenting.

Exercise

Refer to the program on slide #38. What happens if we make five changes
- the 'n' on line #20 to 'a';
- the 'n' on line #25 to 'b';
- the 'n' on line #30 to 'c';
- the 'n' on line #35 to 'd';
- the 'n' on line #40 to 'e',
and then run? What changes on other lines do we need in order to make the program work?

Write a program that prints the following with as few repetitions as you can:


             ******************
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             *                *
             ******************

Write a program that prints the following with as few repetitions as you can:

                  *
                 * *
                *   *
               *     *
              *       *
             *         *
            *           *
           *             *
          *               *
           *             *
            *           *
             *         *
              *       *
               *     *
                *   *
                 * *
                  *

Write a program that prints the following with as few repetitions as you can:

           *
           **
           ***
           ****
           *****
           ******
           *******
           ********
           *********
           **********
           *********
           ********
           *******
           ******
           *****
           ****
           ***
           **
           *

Write a program that prints the following with as few repetitions as you can:

           *  *  *  *  *
            *  *  *  *  *
             *  *  *  *  *
           *  *  *  *  *
            *  *  *  *  *
             *  *  *  *  *
           *  *  *  *  *
            *  *  *  *  *
             *  *  *  *  *
           *  *  *  *  *
            *  *  *  *  *
             *  *  *  *  *

Write a program that prints a multiplication table for 3:

1 3 3

2 3 6

3 3 9

…

…

12 3 36

Write a program that prints the multiplication tables for 2, 3, 4, 5, 6, 7, 8 and 9:

1	2	2
2	2	4
3	2	6
…
…
12	2	24
1	3	3
2	3	6
3	3	9
…
…
12	3	36
1	4	4
2	4	8
3	4	12
…
…
12	4	48
1	5	5
2	5	10
3	5	15
…
…
12	5	60
1	6	6
2	6	12
3	6	18
…
…
12	6	72
1	7	7
2	7	14
3	7	21
…
…
12	7	84
1	8	8
2	8	16
3	8	24
…
…
12	8	96
1	9	9
2	9	18
3	9	27
…
…
12	9	108

Write a program that prints a combined multiplication table for 2, 3, 4, 5, 6, 7, 8 and 9 as follows:

n	2	2*n	3	3*n	4	4*n	5	5*n	6	6*n	7	7*n	8	8*n	9	9*n
1	2	2	3	3	4	4	5	5	6	6	7	7	8	8	9	9
2	2	4	3	6	4	8	5	10	6	12	7	14	8	16	9	18
3	2	6	3	9	4	12	5	15	6	18	7	21	8	24	9	27
…	2		3		4		5		6		7		8		9
…	2		3		4		5		6		7		8		9
12	2	24	3	36	4	48	5	60	6	72	7	84	8	96	9	108

Perl #1

Getting started

Perl #2

Dice

1	2	2
2	2	4
3	2	6
…
…
12	2	24
1	3	3
2	3	6
3	3	9
…
…
12	3	36
1	4	4
2	4	8
3	4	12
…
…
12	4	48
1	5	5
2	5	10
3	5	15
…
…
12	5	60
1	6	6
2	6	12
3	6	18
…
…
12	6	72
1	7	7
2	7	14
3	7	21
…
…
12	7	84
1	8	8
2	8	16
3	8	24
…
…
12	8	96
1	9	9
2	9	18
3	9	27
…
…
12	9	108

n	2	2*n	3	3*n	4	4*n	5	5*n	6	6*n	7	7*n	8	8*n	9	9*n
1	2	2	3	3	4	4	5	5	6	6	7	7	8	8	9	9
2	2	4	3	6	4	8	5	10	6	12	7	14	8	16	9	18
3	2	6	3	9	4	12	5	15	6	18	7	21	8	24	9	27
…	2		3		4		5		6		7		8		9
…	2		3		4		5		6		7		8		9
12	2	24	3	36	4	48	5	60	6	72	7	84	8	96	9	108

1	2	2
2	2	4
3	2	6
…
…
12	2	24
1	3	3
2	3	6
3	3	9
…
…
12	3	36
1	4	4
2	4	8
3	4	12
…
…
12	4	48
1	5	5
2	5	10
3	5	15
…
…
12	5	60
1	6	6
2	6	12
3	6	18
…
…
12	6	72
1	7	7
2	7	14
3	7	21
…
…
12	7	84
1	8	8
2	8	16
3	8	24
…
…
12	8	96
1	9	9
2	9	18
3	9	27
…
…
12	9	108

n	2	2*n	3	3*n	4	4*n	5	5*n	6	6*n	7	7*n	8	8*n	9	9*n
1	2	2	3	3	4	4	5	5	6	6	7	7	8	8	9	9
2	2	4	3	6	4	8	5	10	6	12	7	14	8	16	9	18
3	2	6	3	9	4	12	5	15	6	18	7	21	8	24	9	27
…	2		3		4		5		6		7		8		9
…	2		3		4		5		6		7		8		9
12	2	24	3	36	4	48	5	60	6	72	7	84	8	96	9	108

1	2	2
2	2	4
3	2	6
…
…
12	2	24
1	3	3
2	3	6
3	3	9
…
…
12	3	36
1	4	4
2	4	8
3	4	12
…
…
12	4	48
1	5	5
2	5	10
3	5	15
…
…
12	5	60
1	6	6
2	6	12
3	6	18
…
…
12	6	72
1	7	7
2	7	14
3	7	21
…
…
12	7	84
1	8	8
2	8	16
3	8	24
…
…
12	8	96
1	9	9
2	9	18
3	9	27
…
…
12	9	108

n	2	2*n	3	3*n	4	4*n	5	5*n	6	6*n	7	7*n	8	8*n	9	9*n
1	2	2	3	3	4	4	5	5	6	6	7	7	8	8	9	9
2	2	4	3	6	4	8	5	10	6	12	7	14	8	16	9	18
3	2	6	3	9	4	12	5	15	6	18	7	21	8	24	9	27
…	2		3		4		5		6		7		8		9
…	2		3		4		5		6		7		8		9
12	2	24	3	36	4	48	5	60	6	72	7	84	8	96	9	108