runtime在函數(shù)參數(shù)中使用了類型編碼作為其中一個(gè)參數(shù)，用來(lái)標(biāo)識(shí)函數(shù)的返回值及參數(shù)的類型。
首先類型編碼可以使用@encode()來(lái)查看。
| CODE | MEAN |
|---|---|
| c | A char |
| i | An int |
| l | A long |
| q | A long long |
| C | An unsigned char |
| I | An unsigned int |
| S | An unsigned short |
| L | An unsigned long |
| Q | An unsigned long long |
| f | A float |
| d | A double |
| B | A C++ bool |
| v | A void |
| * | A (char *) |
| @ | An object(id) |
| # | A Class |
| : | A SEL |
| [array type] | An array |
| {name=...} | A structure |
| {name=type...} | A union |
| ? | A unknown type |
這是類型編碼對(duì)應(yīng)的類型
