Similarities and differences between java and object-c (object-c Entry 1)

Basic knowledge of ios:

XCode: You can regard it as a development environment, just like Visual Studio, Netbeans, or SharpDevelop. You can think of Interface Builder as a separate program that is used to draw interfaces in Visual Studio.

Objective-C: This is a language, as if c ++ is a language, Java is a language, c # is a language, and the history of Yingge is also a language.

Cocoa: There are a lot of function libraries, such as MFC,. NET, and Swing. People have already written a bunch of ready-made stuff. You only need to know how to use it.

Some may confuse Objective-C and Cocoa, as if some may confuse c # And. NET. These two things are actually two different things.

Object-c Knowledge:

1. Role of minus signs

Declaration method. obj has no permissions such as public and private.

+ Indicates static, which can be called without instantiation.

Java:

Public void hello (boolean isHello ){

//

}

Obj statement:

-(Void) hello :( BOOL) isHello {

//

}

2. brackets (call method)

This is self in obj, and yes, no is used in Boolean.

Java:

This. hello (true );

Obj:

[Self hello: YES];

3. NS, UI, CA, and so on start with a written function library. You can call it.

NSLog (@ "% d", myInt );

4. nil indicates null.

5, # import is equivalent to importing a package

# Improt and # include are the same

6, @ interface

Obj is implemented after being declared first. The H file declaration, @ interface + @ end, and m file implementation @ implementation + @ end. Isn't it troublesome?

Java:

public class Bird extends Animal{private string name = "tom"private bool isDie(){return true;}}

Obj:

Write a Bird. h file first.

@interface Bird :NSObject {NSString *name;}-(BOOL) isDie;@end

Write another Bird. m file.

#import "Bird.h"@implementation Bird-(void) init{name = @"tom";}-(BOOL) isDie{return YES;}@end

7 multi-parameter Methods

Java:

Public void eat (int count, String name ){

}

Call: this. eat (3, "frog ");

Obj:

Definition

-(Void) eat :( int) count second :( NSString *) name;

Implementation:

-(Void) eat :( int) count second :( NSString *) name {

//

};

Call: [self eat: 3 second @ "frog"]; why is it so troublesome ??

They are all object-oriented languages. They used to learn java. If you have any mistakes, please correct them.