---
# System prepended metadata

title: if && else

---

# if && else
* 
```clike=
if(a) 等同於 if(a != 0),if (a != NULL)
```
* Kernel Code Example
    * #### 假設copy from user回傳的是0,或是NULL就return -EFAULT
```clike=
if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
		return -EFAULT;
```