OCLint的部分规则（Convention 部分）
OCLint的部分规则（Convention 部分）
对OCLint的部分规则进行简单翻译解释，有部分进行了验证以及进一步分析、测试。OCLint其他相关内容如下：
| - | - |
|---|---|
| OCLint-iOS-OC项目几种简单使用 | OCLint的部分规则（Basic 部分） |
| OCLint的部分规则（Unuseed 部分） | OCLint的部分规则（Size 部分） |
| OCLint的部分规则（Redundant 部分） | OCLint的部分规则（Naming 部分） |
| OCLint的部分规则（Migration 部分） | OCLint的部分规则（Empty 部分） |
| OCLint的部分规则（Design 部分） | OCLint的部分规则（Convention 部分） |
| OCLint的部分规则（CoCoa 部分） |
1、avoid branching statement as last in loop
Since:0.7 定义类传送门～点击
Having branching statement as the last statement inside a loop is very confusing, and could largely be forgetting of something and turning into a bug.
简单解释：不要再循环最后加入分支，负责理解起来比较困难，很大程度上会遗忘一些事情，导致一些错误。
void example() {
for (int i = 0; i < 10; i++) {
if (foo(i)) {
continue;
}
break; // this break is confusing
}
}2、base class destructor should be virtual or protected
Since:0.10.2 定义类传送门～点击
Make base class destructor public and virtual, or protected and nonvirtual
简单解释：基类的析构函数需要是
public、virtual或者protected``nonvirtual。
class Base {
public:
~Base(); // this should be either protected or virtual
}
class C : public Base {
virtual ~C();
}Sutter & Alexandrescu (November 2004). [“C++ Coding Standards: 101 Rules, Guidelines, and Best Practices”(http://gotw.ca/publications/c++cs.htm)]. Addison-Wesley Professional
3、unnecessary default statement in covered switch statement
Since:0.8 定义类传送门～点击
When a switch statement covers all possible cases, a default label is not needed and should be removed. If the switch is not fully covered, the SwitchStatements Should Have Default rule will report.
简单解释：如果
switch覆盖了所有的条件，default是不需要的应该被移除。如果不是default还是需要的。
typedef enum {
value1 = 0,
value2 = 1
} eValues;
//
void aMethod(eValues a)
{
switch(a)
{
case value1:
break;
case value2:
break;
default: // this break is obsolete because all
break; // values of variable a are already covered.
}
}4、 ill-placed default label in switch statement
Since:0.6 定义类传送门～点击
It is very confusing when default label is not the last label in a switch statement.
简单解释：
default应该在switch的最后，负责会很难理解。
void example(int a) {
switch (a) {
case 1:
break;
default: // the default case should be last
break;
case 2:
break;
}
}5、destructor of virtual class
Since:0.8 定义类传送门～点击
This rule enforces the destructor of a virtual class must be virtual.
简单解释：这个规则是虚拟类的析构函数必须是虚拟的。
class Base { // class Base should have a virtual destructor ~Base()
public: virtual void f();
};
class Child : public Base {
public: ~Child(); // destructor ~Child() should be virtual
};6、inverted logic
Since:0.4 定义类传送门～点击
An inverted logic is hard to understand.
简单解释：倒置逻辑不易理解。
int example(int a) {
int i;
if (a != 0) // if (a == 0)
{ // {
i = 1; // i = 0;
} // }
else // else
{ // {
i = 0; // i = 1;
} // }
return !i ? -1 : 1; // return i ? 1 : -1;
}PS：在做判断的时候，应该先做的
是判断，在做非的判断。做个一个测试如果只有非的测试是不会有警告的。
int example(int condition) {
int temp;
if (acondition!= 0) //不会有警告
{
temp = 1;
}
}7、missing break in switch statement
Since:0.6 定义类传送门～点击
A switch statement without a break statement has a very large chance to contribute a bug.
简单解释：在
switch语句中缺失了break，很有可能引发bug。
void example(int a) {
switch (a) {
case 1:
break;
case 2:
// do something
default:
break;
}
}8、non case label in switch statement Since:0.6 定义类传送门～点击
It is very confusing when label becomes part of the switch statement.
简单解释：
label出现在switch条件中不易理解。
void example(int a) {
switch (a) {
case 1:
break;
label1: // label in a switch statement in really confusing
break;
default:
break;
}
}9、 ivar assignment outside accessors or init Since:0.8 定义类传送门～点击
This rule prevents assigning an ivar outside of getters, setters, and init method.
简单解释：检查某些成员的初始化不再
getters、settersandinit method中。
@interface Foo : NSObject {
int _bar;
}
@property (assign, nonatomic) int bar;
@end
@implementation Foo
@synthesize bar = _bar;
- (void)doSomething {
_bar = 3; // access _bar outside its getter, setter or init
}
@endPS：简单和小伙伴讨论了下，感觉iOS开发并不是很适合。
10、parameter reassignment Since:0.6 定义类传送门～点击
Reassigning values to parameters is very problematic in most cases.
简单解释：对参数进行重新赋值，在很多情况下是有问题的。
void example(int a) {
if (a < 0) {
a = 0; // reassign parameter a to 0
}
}PS：简单测试了传值时使用指针，经测试不会有警告。也就是说不会对指针类型的参数做检查。
11、prefer early exits and continue Since:0.8 定义类传送门～点击
Early exits can reduce the indentation of a block of code, so that reader do not have to remember all the previous decisions, therefore, makes it easier to understand the code.
简单解释：在有退出语句 的时候，应该让退出语句靠前，这样阅读代码使代码可以很好的被理解。
int *doSomething(int a) {
if (!foo(a) && bar(a) && doOtherThing(a)) {
// ... some really long code ....
}
return 0;
}
// is preferred as
int *doSomething(int a) {
if (foo(a)) {
return 0;
}
if (!bar(a)) {
return 0;
}
if (!doOtherThing(a)) {
return 0;
}
// ... some long code ....
}12、 missing default in switch statements Since:0.6 定义类传送门～点击
Switch statements should have a default statement.
简单解释：检查
Switch中default缺失的情况。
void example(int a) {
switch (a) {
case 1:
break;
case 2:
break;
// should have a default
}
}13、 too few branches in switch statement Since:0.6 定义类传送门～点击
To increase code readability, when a switch consists of only a few branches, it’s much better to use an if statement instead.
简单解释：如果
switch语句条件很少，可以一用if else代替。
void example(int a) {
switch (a) {
case 1:
break;
default:
break;
} // Better to use an if statement and check if variable a equals 1.
}Thresholds:
MINIMUM_CASES_IN_SWITCH The reporting threshold for count of case statements in a switch statement, de-
fault value is 3.