become an xcoder

BECOME AN XCODER

1

mailto:[email protected]

Copyright © 2006 by Bert Altenburg, Alex Clarke and Philippe Mougin. Version 1.2.

Attribution: The licensors, Bert Altenburg, Alex Clarke and Philippe Mougin, permit others to copy,

modify and distribute the work. In return, the licensees must give the original authors credit.

Non-commercial: The licensors permit others to copy, modify and distribute the work and use the

work in paid-for and free courses. In return, licensees may not sell the work itself, although it may

accompany other work that is sold.

BECOME AN XCODER

2

__________________________________________________ 4

0 ______________________________________ 5

1 _____________________________ 7

2 __________________________ 13

3 ______________________________________________ 14

4 _______________________________________ 20

5 _____________________________________ 25

6 __________________________________________ 33

7 while _______________________________ 36

8 GUI ___________________ 39

9 _______________________________________ 55

10 _____________________________________awakeFromNib 59

11 ______________________________________________ 61

12 ______________________________________________ 63

13 ______________________________________________ 69

14 _________________________________________73

15 __________________________________________ 75

BECOME AN XCODER

3

Apple Cocoa

Xcode Mac OS X Apple

Mac

Objective-C Xcode

(GUI)

[4]

[4.3] [4]

volume = baseArea * height; // [4.3]

Xcode

BECOME AN XCODER

4

0

Mac Macintosh

1. Mac Mac Mac

Mac Objective-C AppleScript

AppleScript

AppleScript for Absolute Starters

http://www.macscripter.net/books

2. Macintosh PC

Mac T Mac

Mac Mac

distributed computing, DC

Folding@home SETI@home

DC DC

Mac DC

Mac

DC Mac

Mac

Mac DC

DC

http://distributedcomputing.info/projects.html

3. Macintosh

4. Macintosh

BECOME AN XCODER 0

5

5. Macintosh

DC

BECOME AN XCODER 0

6

1

Xcode

Objective-C

2 + 6 =

= 3 * 4 *

x y

2 + 6 = x

y = 3 * 4

Objective-C

Objective-C statement

[1]

x = 4;

x 4

... [1]

compiler

Mac 0 1

Mac

BECOME AN XCODER 1

7

b u g

debugging

x

pictureWidth [2]

[2]

pictureWidth = 8;

pictureWidth pictureWIDTH PictureWidth

[2]

Objective-C Objective-C

pictureWidth

"_"

door8k do8or do_or

door 8 8door

Door8

[3]

[3]

pictureWidth=8;

pictureHeight=6;

pictureSurfaceArea=pictureWidth*pictureHeight;

BECOME AN XCODER 1

8

[4]

pictureWidth = 8;

pictureHeight = 6;

pictureSurfaceArea = pictureWidth * pictureHeight;

[5]

[5]

pictureWidth = 8;

pictureHeight = 4.5;


integers [5.1] [5.2]

floating-

point

[5]

" "

[6]

int pictureWidth;

float pictureHeight, pictureSurfaceArea;

pictureWidth = 8;



[6.1] int pictureWidth integer

[6.2]

float

pictureWidth int

float pictureSur-

faceArea [6.2]

int float

int float

long long double

BECOME AN XCODER 1

9

[7]

unsigned int chocolateBarsInStock;

unsigned int unsigned int

[8]

[8]

int x = 10;

float y= 3.5, z = 42;

operators

+

-

/

*

Objective-C

x = x + 1; [9] [10]

[9]

x++;

[10]

++x;

x ++

[11] [12]

[11]

x = 10;

BECOME AN XCODER 1

10

y = 2 * (x++);

[12]

x = 10;

y = 2 * (++x);

[11] y 20 x 11 [12.2]

x 2 1 x 11 y 22 [12]

[13]

[13]

x = 10;

x++;

y = 2 * x;

* / + - 2 * 3 + 4 10

2 * (3 + 4) 14

[14, 15]

[14]

int x = 5, y = 12, ratio;

ratio = y / x;

[15]

float x = 5, y = 12, ratio;

ratio = y / x;

[14] 2 [15]

2.4

% % operand

%

[16]

int x = 13, y = 5, remainder;

remainder = x % y;

BECOME AN XCODER 1

11

remainder 3 x 2*y + 3

21 % 7 0

22 % 7 1

23 % 7 2

24 % 7 3

27 % 7 6

30 % 2 0

31 % 2 1

32 % 2 0

33 % 2 1

34 % 2 0

50 % 9 5

60 % 29 2

BECOME AN XCODER 1

12

2

[1]

[1]

float pictureWidth, pictureHeight, pictureSurfaceArea;

pictureWidth = 8.0;



//

Xcode /* */

/*

*/

Xcode

outcomment /* */

BECOME AN XCODER 2

13

3

Objective-C

function

main() main()

main() [1]

[1]

main()

{

// main()

}

[1.1] "main" "main"

main()

[1.2,1.5]

[2]

[2]

main()

{

//


//

BECOME AN XCODER 3

14

pictureWidth = 8.0;


//


}

main()

main()

circleArea() [3]

[3]

main()

{


pictureWidth = 8.0;



}

circleArea() // [3.9]

{

}

[3.9]

main()

circleArea() main() [4]

[4]

main()

{

float pictureWidth, pictureHeight, pictureSurfaceArea,

circleRadius, circleSurfaceArea; // [4.4]

pictureWidth = 8.0;


circleRadius = 5.0; // [4.7]


BECOME AN XCODER 3

15

//

circleSurfaceArea = circleArea(circleRadius); // [4.11]

}

[3]

float [4.4] initialize circleRadius

[4.7] [4.11] circleArea()

circleRadius circleArea() argument

circleRadius circleArea() circleArea()

return [3] circleArea()

[5]

circleArea()

[5]

circleArea(float theRadius) // [5.1]

{

float theArea;

// pi r

theArea = 3.1416 * theRadius * theRadius; //[5.5]

return theArea;

}

[5.1] circleArea()

theRadius theArea [5.5]

[5.3] main [4.4]

theRadius [5.1] [5.6]

[4.11] circleSurfaceArea

[5]

float [6.1]

[6]

float circleArea(float theRadius)

{

float theArea;

theArea = 3.1416 * theRadius * theRadius;

return theArea;

}

BECOME AN XCODER 3

16

[6.1] theArea

float main() circleSurfaceArea

[4.11]

[7]

int throwDice()

{

int noOfEyes;

// 1 6

return noOfEyes;

}

“void”

“return” return

[8]

void beepXTimes(int x);

{

// x

return;

}

pictureSurfaceArea()

[9]

float pictureSurfaceArea(float theWidth, float theHeight)

{

//

}

main() return

0 [10.10] main()

main() "int" [10.1]

[10]

BECOME AN XCODER 3

17

int main()

{


circleRadius, circleSurfaceArea;

pictureWidth = 8;


circleRadius = 5.0;


circleSurfaceArea = circleArea(circleRadius);

return 0; // [10.10]

}

float circleArea(float theRadius) // [10.13]

{

float theArea;


return theArea;

}

[10] [10.1] main() [10.13]

[10.9]

circleArea() main()

warning int main() function

declaration [11.1] [10.13]

[11]

float circleArea(float theRadius); //

int main()

{

[10]

rectangleArea() [12] main()

BECOME AN XCODER 3

18

main()

[12]

float rectangleArea(float length, float width)

{

return (length * width);

}

[12.3]

[10.15] theArea

[12]

rectangleArea

float

float [12.1]

Objective-C

Xcode

[11]

BECOME AN XCODER 3

19

4

Cocoa

NSLog()

" "

NSLog()

Cocoa

NSLog()

[1]

int main()

{

NSLog(@"Julia is a pretty actress.");

return 0;

}

[1] "Julia is a pretty actress." @" "

string

NSLog()

[1]

2005-12-22 17:39:23.084 test[399] Julia is a pretty actress.

character

main()

[2]

NSLog(@"");

NSLog(@" ");

[2.1] empty string

[2.2] space

1

BECOME AN XCODER 4

20

[3.1] \n

[3]

NSLog(@"Julia is a pretty \nactress.");

Julia is a pretty

actress.

[3.1] escape NSLog()

"n" " "

NSLog()

[4]

NSLog(@"Julia is a pretty actress.\\n");

[4.1]

Julia is a pretty actress.\n

[5]

int x, integerToDisplay;

x = 1;

integerToDisplay = 5 + x;

NSLog(@"The value of the integer is %d.", integerToDisplay);

%d % d deci-

mal number %d

integerToDisplay [5]

The value of the integer is 6.

%f %d

[6]

BECOME AN XCODER 4

21

float x, floatToDisplay;

x = 12345.09876;

floatToDisplay = x/3.1416;

NSLog(@"The value of the float is %f.", floatToDisplay);

.2 % f

[7]

float x, floatToDisplay;

x = 12345.09876;

floatToDisplay = x/3.1416;

NSLog(@"The value of the float is %.2f.", floatToDisplay);

% f % d

[8]

int x = 123456;

NSLog(@"%2d", x);

NSLog(@"%4d", x);

NSLog(@"%6d", x);

NSLog(@"%8d", x);

[8]

123456

123456

123456

123456

[8.1, 8.2]

[8.4]

[9]

float x = 1234.5678

NSLog(@"Reserve a space of 10, and show 2 significant digits.");

NSLog(@"%10.2d", x);

BECOME AN XCODER 4

22

[10.3]

%d %f int float

[10]

int x = 8;

float pi = 3.1416;

NSLog(@"The integer value is %d, whereas the float value is %f.", x, pi);

[10b]

int x = 8;

float pi = 3.1416;

NSLog(@"The integer value is %f, whereas the float value is %f.", x, pi);

The integer value is 0.000000, whereas the float value is 0.000000.

NSLog()

import NSLog()

#import <Foundation/Foundation.h>

[11]


float circleArea(float theRadius);

float rectangleArea(float width, float height);

int main()

{



pictureWidth = 8.0;


circleRadius = 5.0;

pictureSurfaceArea = rectangleArea(pictureWidth, pictureHeight);


BECOME AN XCODER 4

23

NSLog(@"Area of circle: %10.2f.", circleSurfaceArea);

NSLog(@"Area of picture: %f. ", pictureSurfaceArea);

return 0;

}

float circleArea(float theRadius) //

{

float theArea;


return theArea;

}

float rectangleArea(float width, float height) //

{

return width * height;

}

BECOME AN XCODER 4

24

5

Mac Mac

compiler Mac

Apple Xcode Mac OS X

X c o d e

http://developer.apple.com

Xcode Developer Applications

Preferences File New Pro-

ject

Xcode

Objective-C GUI Graphical User

Interface Command Line Utility Foundation Tool

BECOME AN XCODER 5

25

justatry

Finish

Terminal

"Groups & Files"

GUI GUI

Xcode "Groups"

Groups & Files justatry Source

justatry.m [1] main()

main()

justatry.m Apple

main()

BECOME AN XCODER 5

26

Xcode main()

[1]


int main (int argc, const char * argv[]) // [1.3]

{

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; // [1.5]

// insert code here...

NSLog(@"Hello, World!");

[pool release]; //[1.9]

return 0;

}

NSLog() import

main()

BECOME AN XCODER 5

27

NSlog

return 0;

main() [1.3]

NSAutoreleasePool [1.5]

pool release [1.9]

" "

main()

[1]

[1.3 1.5 1.9] Objective-

C

main

"pool"

Apple [1] Build and Go

build compile

Build and Go

Run Log

exited stopped 0 main()

[7.9]

[1]

NSLog " "

BECOME AN XCODER 5

28

[2]


int main (int argc, const char * argv[])

{

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

// insert code here...

NSLog(@"Julia is a pretty actress") //

[pool release]; //[2.9]

return 0;

}

Build [2.9]

Xcode

error: parse error before "release".

parse

import

[2.1] # [2.8]

[2.9]

Apple [1] [3]

[3]


float circleArea(float theRadius); // [3.3]

BECOME AN XCODER 5

29

int main (int argc, const char * argv[]) // [3.5]

{


int pictureWidth;

float pictureHeight, pictureSurfaceArea,


pictureWidth = 8;


circleRadius = 5.0;



NSLog(@"Area of picture: %f. Area of circle: %10.2f.",

pictureSurfaceArea, circleSurfaceArea);

[pool release];

return 0;

}

float circleArea(float theRadius) // [3.22]

{

float theArea;


return theArea;

}

float rectangleArea(float width, float height) // [3.29]

{

return width * height;

}

main() cir-

cleArea() [3.22] rectangleArea() [3.29]

main() [3.5] main() Apple

Area of picture: 36.000000. Area of circle: 78.54.

justatry has exited with status 0.

BECOME AN XCODER 5

30

Xcode

Xcode " " breakpoint

Build and Go popup menu

Build and Debug

BECOME AN XCODER 5

31

Xcode debugger

Continue debugger

Mac OS X

Objective-C

GUI

BECOME AN XCODER 5

32

6

[1.2]

[1]

int age = 42;

if (age > 30) // > " "

{

NSLog(@"age is older than thirty."); //[1.4]

}

NSLog(@"Finished."); //[1.6]

[1.2] if...

true

age > 30 [1.4]

[1.6] if

if...else [2]

[2]

int age = 42;

if (age > 30)

{

NSLog(@"age is older than thirty."); //[2.4]

}

else

{

NSLog(@"age is not older thirty."); //[2.7]

}

NSLog(@"Finished."); //[1.6]

[2.7] [2]

[2.2]

==

>

BECOME AN XCODER 6

33

<

>=

<=

!=

-

if

true false

Objective-C true false 1 0 BOOL

"true" 1 YES "false"

0 NO

[3]

int x = 3;

BOOL y;

y = (x == 4); // y 0

AND & &&

OR | ||

[4]

if ( (age >= 18) && (age < 65) )

{

NSLog(@"Probably has to work for a living.");

}

[5]

if (age >= 18)

{

BECOME AN XCODER 6

34

if (age < 65)

{

NSLog(@"Probably has to work for a living.");

}

}

BECOME AN XCODER 6

35

7 while

[1]

[1]




Objective-C

[2]

for

2.7

[2]

int x;

for (x = 1; x <= 10; x++)

{


}

NSLog(@"The value of x is %d", x);

[2] [1.4] 10 x 1

x <= 10 x 1

x x++

x 2 10 10

x 11 x <= 10

[2.6] loop x 11 10

x++

[3]

[3]

float celsius, tempInFahrenheit;

for (tempInFahrenheit = 0; tempInFahrenheit <= 200; tempInFahrenheit =

tempInFahrenheit + 20)

BECOME AN XCODER 7 while

36

{

celsius = (tempInFahrenheit - 32.0) * 5.0 / 9.0;

NSLog(@"%10.2f -> %10.2f", tempInFahrenheit, celsius);

}

0.00 -> -17.78

20.00 -> -6.67

40.00 -> 4.44

60.00 -> 15.56

80.00 -> 26.67

100.00 -> 37.78

120.00 -> 48.89

140.00 -> 60.00

160.00 -> 71.11

180.00 -> 82.22

200.00 -> 93.33

Objective-C

while () { }

do {} while ()

for-loop

false loop

[4]

int counter = 1;

while (counter <= 10)

{

NSLog(@"Julia is a pretty actress.\n");

counter = counter + 1;

}

NSLog(@"The value of counter is %d", counter);

counter 11

do {} while ()

[5]


37

int counter = 1;

do

{

NSLog(@"Julia is a pretty actress.\n");

counter = counter + 1;

}

while (counter <= 10);

NSLog(@"The value of counter is %d", counter);

counter 11

GUI


38

8 GUI

Objective-C

GUI Objective-C C

C Objective-C C

"Objective" Objective-C object

Objective-C

Objective-C

Objective-C

Safari Objective-C

Mac Safari

message

BECOME AN XCODER 8 (GUI)

39

close

Safari

Safari Apple

a.

b. template Safari

b class

behave

instance 76


40

Mac minimize

Dock

access

close " "

close methods

RAM

button text field

close


41

Mac

message sending expression

Objective-C [1.1] [1.2]

[1]

[receiver message];

[receiver message:argument];

[1.2]

Xcode Application

Cocoa Application GUI

Xcode Groups & Files Resources

MainMenu.nib Double-click


42

Xcode MainMenu.nib

Interface Builder File

Hide Others "Window"

"Window"

"Cocoa-" GUI

" " palettes window

GUI "Window"

"System Font Text" GUI

GUI


43

NSButton

NSTextView Apple

"Window"

p r o p e r t i e s c o m m a n d - s h i f t -

i "Window" In-

stances command-shift-i

pop-up menu Attributes Textured Window

brushed-steel look

Interface Builder inspector

behavior

inherit Objective-C C


44

NSWindow

"close"

" " superclass

hierarchy of inheritance

Objective-C sig-

nal error

implement

override

Apple

Apple

Apple close

invoke close

close recursive

[2]

//

[super close]; // close

"NSObject"

NSObject subclass NSWindow NSResponder

NSObject NSObject

MainMenu.nib Classes NSObject

Classes Subclass NSObject MainMenu.nib

"MAFoo"


45

MAFoo

MAFoo My Application

NS NS Apple NextStep

Apple Next, Inc. NextStep Mac OS X Steve

Jobs

CocoaDev wiki

http://www.cocoadev.com/index.pl?ChooseYourOwnPrefix

Cocoa NSWindow

NSColor MAFoo

Interface Builder Classes Instantiate MAFoo In-

stances MAFoo

MAFoo


46

MAFoo

MAFoo

reference

MAFoo MAFoo

MAFoo

MAFoo

MAFoo MAFoo MAFoo

MAFoo MAFoo trig-

ger FAFoo

outlet

MainFile.nib Classes MAFoo

command-shift-i inspector inspector

Action Add action MAFoo

"setTo5:"

5 Interface Builder

"reset:" 0

":"


47

MAFoo

inspector Outlet outlet "text-

Field"

outlet MAFoo

MAFoo 5 "Set to 5"

"Reset"


48

a) "Reset" MAFoo

b) "Set to 5" MAFoo

c) MAFoo

MainFile.nib Instances Control

Reset MaFoo

MAFoo

MAFoo

inspector MAFoo

"reset:" Connect


49

inspector

MAFoo reset:

Set to 5 MAFoo

MAFoo MAFoo control

Connect

MainMenu.nib MAFoo Classes

MAFoo Classes

Create Files for MAFoo Interface Builder


50

MAFoo

Xcode Other

Sources

Classes

Xcode


51

4 [11.1]

MAFoo.h header file

[3.5] NSObject

NSObject

[3]

/* MAFoo */

#import <Cocoa/Cocoa.h> // [3.3]

@interface MAFoo : NSObject

{

IBOutlet id textField; // [3.7]

}

- (IBAction)reset:(id)sender;

- (IBAction)setTo5:(id)sender;

@end

[3.7] outlet "id" "IB" Interface Buil-

der

IBAction [3.9 3.10] void

MAFoo

Interface Builder Actions

#import <Foundation/Foundation.h> [3.3]

MAFoo.m

[4]

#import "MAFoo.h"

@implementation MAFoo

- (IBAction)reset:(id)sender // [4.5]

{

}


52

- (IBAction)setTo5:(id)sender

{

}

@end

MAFoo.h

reset: setTo5:

MAFoo

Interface Builder MAFoo

MAFoo [5.7 5.12]

[5]

#import "MAFoo.h"


- (IBAction)reset:(id)sender

{

[textField setIntValue:0]; // [5.7]

}


{

[textField setIntValue:5]; // [5.12]

}

@end

textField outlet

Interface Builder outlet

setIntValue: setIntValue:

Xcode Build

and Go


53


54

9

Apple setIntValue:

Apple

bug-free

Interface Builder

"NSButton"

''System Font Text" "NSTextField"

NSTextField

Xcode Help->Documentation Cocoa

"NSTextField" API-Search

NSText-

Field

NSTextField Class NSTextField

BECOME AN XCODER 9

55

Xcode Cocoa

NSObject

Method Types

NSTextField

NSControl NSView

HTML Inherits from

NSControl NSControl

NSControl

Inherits from NSView : NSResponder : NSObject

Setting the control s value

– setIntValue:

BECOME AN XCODER 9

56

setIntValue:

setIntValue:

- (void)setIntValue:(int)anInt

Sets the value of the receiver’s cell (or selected cell) to

the integer anInt. If the cell is being edited, it aborts all

editing before setting the value; if the cell doesn’t inherit

from NSActionCell, it marks the cell’s interior as needing to

be redisplayed (NSActionCell performs its own updating of

cells).

NSTextField

signature

Objective-C

void setInt-

Value: textField MAFood

(int) anInt

5 0

textField

" " Accessors

setIntValue:

[1]

- (int) intValue

textfield

[2]

resultReceived = [textField intValue];

Objective-C

BECOME AN XCODER 9

57

"

" polymorphism object-oriented programming

run-time

GUI setIntValue:

BECOME AN XCODER 9

58

10 awakeFromNib

Apple

framework [12] Foundation Kit

Application Kit

GUI

nib nib Next Interface Buil-

der Application Kit

Xcode Help Documentation

Full-Text Search

Full-Text Search Ap-

plication Kit Return Xcode Applica-

tion Kit Reference for Objective-C

Protocols NSNibAwakening

NSNibAwaking

Declared in AppKit/NSNibLoading.h

Programming Topic Loading Resources

Contents:Protocol DescriptionMethod TypesInstance Methods

Protocol Description

This informal protocol consists of a single method, awakeFrom-

Nib. Classes can implement this method to perform final ini-

tialization of state after objects have been loaded from an

Interface Builder archive.

BECOME AN XCODER 10 awakeFromNib

59

nib

MAFoo.m [1.15]

[1]

#import "MAFoo.h"


- (IBAction)reset:(id)sender

{

[textField setIntValue:0];

}


{


}

- (void)awakeFromNib // [1.15]

{


}

@end

awakeFromNib

BECOME AN XCODER 10 awakeFromNib

60

11

C

- pointer

- Objective-C

Mac

[1]

int x = 4;

Mac

x

[1] int

x long long double

"x = 4" 4 x

x address

x

x

pointer

& x

&x

expression x evaluate x

4 &x x

[2]

int *y;

y int y

x x y

BECOME AN XCODER 11

61

[3]

y = &x;

*y

4 "x"

*y = 5

"x = 5"

1

[4]

void increment(int *y)

{

*y = *y + 1;

}

[5]

int x = 4;

increment(&x);

// x 5

BECOME AN XCODER 11

62

12

integer long float

double BOOL pointer

string NSLog()

%

%d

[1]

float piValue = 3.1416;

NSLog(@"Here are three examples of strings printed to the screen.\n");

NSLog(@"Pi approximates %10.4f.\n", piValue);

NSLog(@"The number of eyes of a dice is %d.\n", 6);

NSString NSMutableString NSString

[2]

NSString *favoriteComputer;

favoriteComputer = @"Mac!";

NSLog(favoriteComputer);

[2.1]

11

[2]

[3]

int *y;

y [2.1]

favoriteComputer NSString

Objective-C

@ Objective-C C

C Objective-C

Objective-C @

BECOME AN XCODER 12

63

Objective-C C Objective-C Uni-

code ASCII Unicode

[4]

[4]

NSString *favoriteActress = @"Julia";

favoriteActress "Julia"

favoriteComputer

[5] NSString

[5]


int main (int argc, const char *argv[])

{


NSString *x;

x = @"iBook"; // [5.7]

x = @"MacBook Pro Intel"; //

NSLog(x);

[pool release];

return 0;

}

MacBook Pro Intel

NSString immutable

Objective-C

BECOME AN XCODER 12

64

NSMutableString

length [6]

[6]



{


int theLength;

NSString * foo;

foo = @"Julia!";

theLength = [foo length]; // [6.10]

NSLog(@"The length is %d.", theLength);

[pool release];

return 0;

}

The length is 6.

foo bar

x

[6.10] foo length length NSString

- (unsigned int)length

Returns the number of Unicode characters in the receiver.

[7]

uppercaseString

NSString

[7]

BECOME AN XCODER 12

65



{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

NSString *foo, *bar;

foo = @"Julia!";

bar = [foo uppercaseString];

NSLog(@"%@ is converted into %@.", foo, bar);

[pool release];

return 0;

}

Julia! is converted into JULIA!

NSMutableString NSMutableString

appendString:

[8]



{


NSMutableString *foo; // [8.7]

foo = [@"Julia!" mutableCopy]; // [8.8]

[foo appendString:@" I am happy"];

NSLog(@"Here is the result: %@.", foo);

[pool release];

return 0;

}

BECOME AN XCODER 12

66

Here is the result: Julia! I am happy.

[8.8] mutableCopy NSString

mutable [8.8] foo

"Julia!"

Objective-C

[8.7] Objective-

C " " " "

" "

[8.7] foo "Julia!"

foo bar

bar = foo;

foo bar

foo [foo dosomething];

bar [bar dosomething];

[9]


"foo"

"foo"

"bar"

BECOME AN XCODER 12

67


{


NSMutableString *foo = [@"Julia!" mutableCopy];

NSMutableString *bar = foo;

NSLog(@"foo points to the string: %@.", foo);

NSLog(@"bar points to the string: %@.", bar);

NSLog(@"------------------------------");

[foo appendString:@" I am happy"];

NSLog(@"foo points to the string: %@.", foo);

NSLog(@"bar points to the string: %@.", bar);

[pool release];

return 0;

}

foo points to the string: Julia!

bar points to the string: Julia!

------------------------------

foo points to the string: Julia! I am happy

bar points to the string: Julia! I am happy

8

MAFoo

BECOME AN XCODER 12

68

13

array

index

element

1

1

NSArray NSMutableArray

[NSMutableArray array]

… …

NSMutableArray

Objective-C

meta-classes

Cocoa

"+" "-" 8 [4.5]

array

array

+ (id)array

BECOME AN XCODER 13

69

Creates and returns an empty array. This method is used by mu-

table subclasses of NSArray.

See Also: + arrayWithObject:, + arrayWithObjects:

[1]



{


NSMutableArray *myArray = [NSMutableArray array];

[myArray addObject:@"first string"];

[myArray addObject:@"second string"];

[myArray addObject:@"third string"];

int count = [myArray count];

NSLog(@"There are %d elements in my array", count);

[pool release];

return 0;

}

There are 3 elements in my array

0

objectAtIndex: [2.13]

[2]



{

BECOME AN XCODER 13

70






NSString *element = [myArray objectAtIndex:0]; // [2.13]

NSLog(@"The element at index 0 in the array is: %@", element);

[pool release];

return 0;

}

The element at index 0 in the array is: first string

[3]



{






int i;

int count;

BECOME AN XCODER 13

71

for (i = 0, count = [myArray count]; i < count; i = i + 1)

{

NSString *element = [myArray objectAtIndex:i];

NSLog(@"The element at index %d in the array is: %@", i, element);

}

[pool release];

return 0;

}

The element at index 0 in the array is: first string

The element at index 1 in the array is: second string

The element at index 2 in the array is: third string

NSArray NSMutableArray

replace

replaceObjectAtIndex:withObject:

Objective-C

[4]

[myArray replaceObjectAtIndex:1 withObject:@"Hello"];

1 @"Hello"

valid

Objective-C

" " Smalltalk

Objective-C expressive

" "

Objective-C

BECOME AN XCODER 13

72

14

Mac RAM

free

destroy

Cocoa

" " retain count

1

2

3

=

3

BECOME AN XCODER 14

73

retain

release Cocoa "autore-

lease pool" release -

autorelease pool

autorelease autorelease pool release

autorelease pool

autorelease pool

Cocoa reference count-

ing 15 Cocoa

Apple Apple Cocoa

automatic garbage collection

Apple

Apple 2006 WWDC World Wide Developer Conference

2007 Xcode 3.0 automatic garbage collection

Objective-C 2.0

BECOME AN XCODER 14

74

15

Xcode Objective-C

Apple

Apple

http://www.apple.com/developer

http://osx.hyperjeff.net/reference/CocoaArticles.php

http://www.cocoadev.com

http://www.cocoabuilder.com

http://www.stepwise.com

http://lists.apple.com/mailman/listinfo/cocoa-dev cocoa-dev

mailing list

http://www.cocoabuilder.com

http://www.catb.org/~esr/faqs/smart-questions.html "How To Ask Questions The

Smart Way" " " http://mis.ndhu.edu.tw/docu/

question.htm

Cocoa Stephen Kochan Programming in Objective-C

Big Nerd Ranch Aaron Hillegass Cocoa Programming for Mac OS X

Xcode James Duncan Davidson Apple O'Reilly Cocoa

with Objective-C

Mac

A p p l e

http://developer.apple.com/documentation/UserExperience/Conceptual/OSXHIGuid

elines/index.html

BECOME AN XCODER 15

75

Xcode 0

Bert, Alex, Philippe.

BECOME AN XCODER 15

76

become an xcoder

Technology

float picturewidth

x picturewidth

float thearea thearea

circlesurfacearea picturewidth

return thearea

c thearea h1

float height

cu float