【Python實作】直式與橫式九九乘法表｜練習for迴圈

Python實作－九九乘法表的寫法與解析

目的：練習for迴圈

關於for迴圈：【Python自學】for迴圈的基本觀念

九九乘法表

 

#進入程式

for i in range(1, 10):      # 外層：控制「被乘數」

    for j in range(1, 10):  # 內層：控制「乘數」

        print(f"{i} x {j} = {i*j}")

    print()  # 換行，讓每個 i 結束後空一行

 

#程式結束

 

程式執行結果：

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

 

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

 

3 x 1 = 3

3 x 2 = 6

3 x 3 = 9

3 x 4 = 12

3 x 5 = 15

3 x 6 = 18

3 x 7 = 21

3 x 8 = 24

3 x 9 = 27

 

4 x 1 = 4

4 x 2 = 8

4 x 3 = 12

4 x 4 = 16

4 x 5 = 20

4 x 6 = 24

4 x 7 = 28

4 x 8 = 32

4 x 9 = 36

 

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

 

6 x 1 = 6

6 x 2 = 12

6 x 3 = 18

6 x 4 = 24

6 x 5 = 30

6 x 6 = 36

6 x 7 = 42

6 x 8 = 48

6 x 9 = 54

 

7 x 1 = 7

7 x 2 = 14

7 x 3 = 21

7 x 4 = 28

7 x 5 = 35

7 x 6 = 42

7 x 7 = 49

7 x 8 = 56

7 x 9 = 63

 

8 x 1 = 8

8 x 2 = 16

8 x 3 = 24

8 x 4 = 32

8 x 5 = 40

8 x 6 = 48

8 x 7 = 56

8 x 8 = 64

8 x 9 = 72

 

9 x 1 = 9

9 x 2 = 18

9 x 3 = 27

9 x 4 = 36

9 x 5 = 45

9 x 6 = 54

9 x 7 = 63

9 x 8 = 72

9 x 9 = 81

 

【說明】

外迴圈：for i in range(1, 10):

內迴圈：for j in range(1, 10):

 

當i = 1（外迴圈）進到內迴圈之後，j = 1，印出1*1=1

回到內迴圈（i 還是 1），j = 2，印出1*2=2

回到內迴圈（i 還是 1），j = 3，印出1*3=3

……

直到內迴圈的j跑完之後，才跑到外迴圈，i = 2，再次進入內迴圈

……

由此跑完所有的流程。

 

橫式九九乘法表

 

#進入程式

for i in range(1, 10):

    for j in range(1, 10):

        print(f"{i}x{j}={i*j:2}", end="\t")  # 不換行，用 \t 對齊

    print()  # 每列結束後換行

 

#程式結束

 

程式執行結果：

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   

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

3 x 1 = 3    3 x 2 = 6    3 x 3 = 9    3 x 4 = 12 3 x 5 = 15 3 x 6 = 18 3 x 7 = 21 3 x 8 = 24 3 x 9 = 27

4 x 1 = 4    4 x 2 = 8    4 x 3 = 12 4 x 4 = 16 4 x 5 = 20 4 x 6 = 24 4 x 7 = 28 4 x 8 = 32 4 x 9 = 36

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

6 x 1 = 6    6 x 2 = 12 6 x 3 = 18 6 x 4 = 24 6 x 5 = 30 6 x 6 = 36 6 x 7 = 42 6 x 8 = 48 6 x 9 = 54

7 x 1 = 7    7 x 2 = 14 7 x 3 = 21 7 x 4 = 28 7 x 5 = 35 7 x 6 = 42 7 x 7 = 49 7 x 8 = 56 7 x 9 = 63

8 x 1 = 8    8 x 2 = 16 8 x 3 = 24 8 x 4 = 32 8 x 5 = 40 8 x 6 = 48 8 x 7 = 56 8 x 8 = 64 8 x 9 = 72

9 x 1 = 9    9 x 2 = 18 9 x 3 = 27 9 x 4 = 36 9 x 5 = 45 9 x 6 = 54 9 x 7 = 63 9 x 8 = 72 9 x 9 = 81

 

邏輯是一樣的，只是print字串方法後面加了（\t），讓每一行結束之後變成空格四格，預設是換行。