iOS face Test 9

iOS face test 9
1. When you use Xcode to create a project, the version management library that supports simultaneous creation is (C)
A.subversion
B.mercurial
C.git
D.concurrent Version System


2.UIEdgeInsets edgeinsets = Uiedgeinsetsmake (10,10,10,10);
@synchronized (edgeinsets) {}


About this code, the correct statement: (D)
A. Code written inside curly braces that will ensure multithreaded access edgeinsets not error
B. Uiedgeinsetsmake is a method of constructing uiedgeinsets data types
C. Uiedgeinsets is essentially the basic data type in OC
D. Code Errors


Explain
Only the object type ID can be stored, and now is a basic data type


Uiedgeinsets is a special type, and Nsrange,cgrect is essentially a struct type.
Because OC does not have a namespace, it can only be distinguished using prefixes, but many of the non-object types in OC use the same prefix as the object type, paying attention to the screening (general non-object types are created with no * numbers, except IDs)
@synchronized used to protect the object being accessed can have only one thread at a time, ensuring that the thread accesses the object without error.


3. How to add a child view, which is the embodiment of object-oriented features. C
A. Package B. Inherit C. Polymorphism D. Protocol


Polymorphism: Addsubview parent class pointer to subclass object
View Type-label


4. Excellent program design, which should follow the following guidelines. B
A. High cohesion, high coupling
B. High cohesion, low coupling
C. Low cohesion, high coupling
D. Low cohesion, low coupling


5. When creating Windows for an application, which of the following is the necessary reason for declaring a property. B
A. The inside of a class can be accessed
B. External access to the class
C. Extension of the Declaration cycle
D. copy window copy




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