【1】原代碼

 1 // 重構前
 2 QString foundPerson(QStringList people)
 3 {
 4     QString found = QString();
 5     for (int i = 0; i < people.size(); ++i)
 6     {
 7         if (people[i].compare("Don") == 0)
 8         {
 9             found = "Don";
10         }
11 
12         if (people[i].compare("
 
John") == 0)
13         {
14             found = "John";
15         }
16 
17         if (people[i].compare("Dave") == 0)
18         {
19             found = "Dave";
20         }
21     }
22 
23     return found;
24 }

【2】移除控制標記

 1 // 重構後
 2 QString foundPerson(QStringList people)
 3 {
 
 4     QStringList candidates = {"Don", "John", "Dave"};
 5     for (int i = 0; i < people.size(); ++i)
 6     {
 7         if (candidates.contains(people[i]))
 8         {
 9             return people[i];
10         }
11     }
12 
13     return QString();
14 }

【3】總結

在一系列布爾表達式中，某個變量帶有“控制標記”（control flag）的作用。以break語句或return語句取代控制標記。

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4.4 移除控制標記