Basic Pascal Tutorial/Chapter 4/Functions/zh CN: what changed
Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.
Title: Basic Pascal Tutorial/Chapter 4/Functions/zh CN
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| 1 | + | 4C - 函数 (原作者: Tao Yue, 状态: 未更改) | |
| 2 | + | ||
| 3 | + | 函数的工作方式和过程相似;不同的是,函数总要有返回值,通过给函数名赋值确定返回值。 | |
| 4 | + | ||
| 5 | + | ``` pascal | |
| 6 | + | function Name (参数列表) : 返回类型; | |
| 7 | + | ``` | |
| 8 | + | ||
| 9 | + | 过程不能直接参与运算,函数可以。在表达式中使用函数进行运算: | |
| 10 | + | ||
| 11 | + | ``` pascal | |
| 12 | + | a := Name (5) + 3; | |
| 13 | + | ``` | |
| 14 | + | ||
| 15 | + | 如果你的函数没有参数,要注意不要在右侧的功能内的任何公式使用函数的名称。是: | |
| 16 | + | ||
| 17 | + | 如果定义的函数没有参数,不要在函数体内部使用与函数名相同的名称: | |
| 18 | + | ||
| 19 | + | ``` pascal | |
| 20 | + | function Name : integer; | |
| 21 | + | begin | |
| 22 | + | Name := 2; | |
| 23 | + | Name := Name + 1 | |
| 24 | + | end. | |
| 25 | + | ``` | |
| 26 | + | ||
| 27 | + | 这是被禁止的,想像一下,无限递归调用自己…… | |
| 28 | + | ||
| 29 | + | 通过给函数名赋值来设置返回值。 | |
| 30 | + | ||
| 31 | + | ``` pascal | |
| 32 | + | Name := 5; | |
| 33 | + | ``` | |
| 34 | + | ||
| 35 | + | 函数最好不要使用按引用(地址)传递参数——函数应该只有一个返回值。 | |
| 36 | + | ||
| 37 | + | 你肯定不希望使用sin函数时,却改变了pi值吧?它的结果只为0。 | |
| 38 | + | ||
| 39 | + | | | | | | |
| 40 | + | |----|----|----| | |
| 41 | + | | [[Basic Pascal Tutorial/Chapter 4/Parameters/zh CN|上一页]] | [[Basic Pascal Tutorial/Contents/zh CN|目录]] | [[Basic Pascal Tutorial/Chapter 4/Scope/zh CN|下一页]] | | |
| 42 | + | ||
| 43 | + | --- | |
| 44 | + | *From the Free Pascal wiki, page "Basic Pascal Tutorial/Chapter 4/Functions/zh CN", as it stood on 2022-08-20 after a change by Kai Burghardt, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).* |
