(1)create class’s object and initialize property

create a project

in projectname.m:

#import <Foundation/Foundation.h>
#import "song.h"
int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    // insert code here...
    NSLog(@"Hello, World!");
	
	song *s1=[[song alloc] initwithname:@"two tiggers"
							 get_artist:@"libai"
							  get_price:20];
	song *s2=[[song alloc] initwithartist:@"wangwei"
							 get_name:@"three pigs"
							  get_price:30];	
	song *s3=[[song alloc] initwithprice:40];
	
	NSLog(@"s1:%@",s1);
	NSLog(@"s2:%@",s2);
	NSLog(@"s3:%@",s3);
	
	[s1 release];
	[s2 release];
	[s3 release];
	
    [pool drain];
    return 0;
}
 

create a song class

statement in song.h:

#import <Cocoa/Cocoa.h>

@interface song : NSObject {

	NSString *name;
	NSString *artist;
	int price;
}

-(NSString *)get_name;
-(NSString *)get_artist;
-(int)get_price;

-(void)set_name:(NSString *)newname;
-(void)set_artist:(NSString *)newartist;
-(void)set_price:(int)newprice;

-(id)initwithname:(NSString *)newname get_artist:(NSString *)newartist get_price:(int)newprice;
-(id)initwithartist:(NSString *)newartist get_name:(NSString *)newname get_price:(int)newprice;
-(id)initwithprice:(int)newprice;
 

implementation in song.m:

#import "song.h"

@implementation song

//song get and set property's api

-(NSString*)get_name
{
	return name;
}

-(NSString *)get_artist
{
	return artist;
}

-(int)get_price
{
	return price;
}

-(void )set_name:(NSString*)newname
{
	[newname retain];
	[name release];
	name=newname;
}

-(void )set_artist:(NSString*)newartist
{
	[newartist retain];
	[artist release];
	artist=newartist;
}

-(void)set_price:(int)newprice
{
	price=newprice;
}

//rewrite father api

-(id)init
{
	return [self initwithname:nil get_artist:nil get_price:0];
}

-(NSString *)description
{
	
	return [[self get_name] stringByAppendingString:[self get_artist]];
}

-(void)dealloc
{
	NSLog(@"dealloc %@",self);
	[name release];
	[artist release];
	[super dealloc];
}

//write my api

-(id)initwithname:(NSString*)newname get_artist:(NSString *)newartist get_price:(int)newprice
{
	[super init];
	[self set_name:newname];
	[self set_artist:newartist];
	[self set_price:newprice];
	return self;
}

-(id)initwithartist:(NSString *)newartist get_name:(NSString *)newname get_price:(int)newprice
{
	[super init];
	[self set_name:newname];
	[self set_artist:newartist];
	[self set_price:newprice];
	return self;
}

-(id)initwithprice:(int)newprice
{
	[super init];
	[self set_price:newprice];
	return self;
}

@end

 

(2)use string

	NSString * [email protected]"one two three,oh oh oh yes";
	NSRange range=[string1 rangeOfString:@","];
	printf("comma location:%i\n", range.location);
	printf("location length:%i\n", range.length);
	
	NSString * head=[string1 substringToIndex:range.location];
	NSString * tail=[string1 substringFromIndex:range.location + range.length];
	
	printf("head:%s\n",[head UTF8String]);
	printf("tail:%s\n",[tail UTF8String]);
	
	NSMutableString*string2=[[NSMutableString alloc] init];
	[string2 appendString:@"add string2"];
	printf("append string2:%s\n",[string2 UTF8String]);
	
	[string2 replaceCharactersInRange:[string2 rangeOfString:@"add"] withString:@"replace"];
	printf("replace string2:%s\n",[string2 UTF8String]);
	
	NSRange range2=[string2 rangeOfString:@"ing"];
	[string2 deleteCharactersInRange:(NSRange)range2];
	printf("delete string2:%s\n",[string2 UTF8String]);
	
	[string2 insertString:@"ong" atIndex:range2.location];
	printf("insert string2:%s\n",[string2 UTF8String]);
	
	[string2 release];

(3)get filename

	NSString * filename [email protected]"~/Documents/se0864/10-25/get_filename/get_file/get_file.m";
	//NSString * filename [email protected]"/Users/se0030a/Documents/se0864/10-25/get_filename/get_file/get_file.m";
	filename=[filename stringByStandardizingPath];
	printf("standard path:%s\n",[filename UTF8String]);
	
	NSString * source=[NSString stringWithContentsOfFile:filename];
	printf("file content:%s\n",[source UTF8String]);
	

(4)load a string into a array

	NSString * string = @"I am find Thank you";
	NSArray * array = [string componentsSeparatedByString:@" "];
	int count = [array count];
	int i;
	for(i=0;i<count;i++)
	{
		printf("%i:%s\n",i,[[array objectAtIndex:i] UTF8String]);
	}
	
	[string writeToFile:@"/Users/se0030a/Documents/se0864/10-25/1.txt" atomically:1];
	
	printf("%i\n",[array containsObject:@"find"]);
	printf("%i\n",[array containsObject:@"fond"]);	

mutable array:

	NSMutableArray * array = [[NSMutableArray alloc] init];
	[array addObject:@"b"]; //b
	[array addObject:@"black"]; //black
	[array addObject:@"crow and kid"]; //"crow and kid"
	[array addObject:@"play waterball"]; //"play waterball"
	printf("%s\n",[[array description] UTF8String]);
	
	[array insertObject:@"very" atIndex:[array indexOfObject:@"black"]];
	printf("%s\n",[[array description] UTF8String]);
	
	[array removeObjectAtIndex:1];
	printf("%s\n",[[array description] UTF8String]);
	
	[array removeObject:@"black"];
	printf("%s\n",[[array description] UTF8String]);	
	
	[array removeObject:@"blue"];
	printf("%s\n",[[array description] UTF8String]);
	
	[array release];
	

(5)address book

#import <Foundation/Foundation.h>
#import <AddressBook/AddressBook.h>
int main (int argc, const char * argv[]) 
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    ABAddressBook * book = [ABAddressBook sharedAddressBook];//get a addressbook for user
	NSArray * people = [book people];//get a array which contains all people in book
	
	int count = [people count];
    int i;
	for(i=0;i<count;i++)
	{
		ABPerson * person = [people objectAtIndex:i];//get a object on book array
		NSString * firstname = [person valueForProperty:@"First"];
		NSString * lastname = [person valueForProperty:@"Last"];
		printf("%s %s\n",[lastname UTF8String],[firstname UTF8String]);
	}
	
	[pool drain];
    return 0;
}

(6)dictionaries

	//using dictionaries
	NSArray * keys = [@"one two three four five" componentsSeparatedByString:@" "];
	NSArray * values = [@"aaa,bbb,ccc,ddd,eee" componentsSeparatedByString:@","];

	NSDictionary * dict = [[NSDictionary alloc] initWithObjects:values
														forKeys:keys];
	printf("%s\n",[[dict description] UTF8String]);
	
	//using mutable dictionaries
	NSArray * keys2 = [@"one two three four five" componentsSeparatedByString:@" "];
	NSArray * values2 = [@"a,b,c,d,e" componentsSeparatedByString:@","];
	
	NSMutableDictionary * dict2 = [[NSMutableDictionary alloc] initWithObjects:values2
														forKeys:keys2];
	printf("%s\n",[[dict2 description] UTF8String]);
	
	[dict2 setObject:@"e" forKey:@"four"];
	[dict2 setObject:@"f" forKey:@"six"];
	[dict2 removeObjectForKey:@"one"];
	printf("%s\n",[[dict2 description] UTF8String]);