Take notes on ios development and take notes on ios development

Take notes on ios development and take notes on ios development

+-Symbol before the Method

The method of the plus sign (+) is a class method, which can be called directly by class name. Its function is mainly to create an instance. It is equivalent to a static method.

The method of minus sign (-) is an instance method, which can be called only by using an instance of the class.

To declare a member variable as static, the static keyword must be used.


Questions about the parameters of Ob-c Functions

A Method of Object-c can contain multiple parameters. Except for the first parameter, all subsequent parameters must be named.
Writing multiple parameters

(Method data type) function name: (parameter 1 data type) value of parameter 1 Name of parameter 2 Name: (parameter 2 data type) Name of parameter 2 value .... ;

For example, the definition of a method:

-(Void) setKids: (NSString *) myOldestKidName secondKid: (NSString *) mySecondOldestKidName thirdKid: (NSString *) myThirdOldestKidName;

When implementing this function:

-(Void) setKids: (NSString *) myOldestKidName secondKid: (NSString *) mySecondOldestKidName thirdKid: (NSString *) myThirdOldestKidName {

Eldest Son = myOldestKidName;

Second son = mySecondOldestKidName;

Son 3 = myThirdOldestKidName;

}

When calling:

Kids * myKids = [[Kids alloc] init];

[MyKids setKids: @ "" secondKid: @ "" thirdKid: @ ""];

However, if you use c # To write this method, the general statement may be:

Public void setKids (string myOldestKidName, string mySecondOldestKidName, string myThirdOldestKidName)

{

...

}

The calling method may be as follows:

Kids myKids = new Kids ();

MyKids. setKids ("Zhang Dali", "Zhang erli", and "Zhang Xiaoli ");

Do you understand? In fact, it is not difficult to understand.

Basically, if you can understand the Conversion Relationship of the following code, your Objective-C syntax can be roughly achieved:

[[MyClass alloc] init: [foo bar] autorelease];

The syntax for converting to C # or Java is:

MyClass. alloc (). init (foo. bar (). autorelease ();