Sort of Nsarray

Nsarray derivation of a new collection

-(Nsarray *) Arraybyaddingobject: (ID) anobject

Add a new Array,and return a new Nsarray

-(Nsarray *) Arraybyaddingobjectsfromarray: (Nsarray *) Anotherarray

Add all the elements Inanother array and return a new Nsarray original array not change

-(Nsarray *) Subarraywithrange: (nsarray) Range

Load elements within range

#pragma derive a new array

void Arraynew () {

Nsarray *array=[nsarray arraywithobjects:@ "1", @ "2", nil];

Nsarray *array2=[arrayarraybyaddingobject:@ "3"];//merged array

The original array did not change, just the return array2 changed.

Nsarray *array3=[arrayarraybyaddingobjectsfromarray:[nsarray arraywithobject:@ "4", @ "5", NIL]];//4 elements

Nsarray *array4=[array arraywithobjects:@ "1", @ "2", @ "3", @ "4", nil];

Nsrange range= nsmakerange (n);

Nsarray *array5=[array4 Subarraywithrange:range];

}

Other method.

-(NSString) componentsjoinedbystring: (NSString *) seperator

Use a seperator to joint all the elements as a string

Use a delimiter to stitch all the elements in an array into a single string

-(BOOL) write to File: (NSString *) path atomically: (bool) Use Auxiliaryfile

Persist a nsarray to a file

#pregma Mark Other method

void Arrayother () {

Nsarray *array=[array arraywithobjects:@ "1", @ "2", @ "3", @ "4", nil];

NSString *string=[array componentsjoinedbystring:@ ","];//1,2,3,4

NSString *[email protected] "/users/apple/desktop/array.xml";

[Arry writetofile:path atomically:yes];//create a XML file

Reading array contents from a file (file has strict formatting requirements)

NSString *[email protected] "/users/apple/desktop/array.txt";

Nsarray *array2=[nsarray Arraywithcontentsoffile:path];

}

Nsarray Sort 1

-(Nsarray *) Sortedarrayusingselector: (SEL) Comparator

Return a new sorted array, original array won't change

#pragma Mark ArraySort

void ArraySort1 () {

Nsarray *array=[array arraywithobjects:@ "2", @ "3", @ "1", @ "4", nil];

Nsarray *array2=[array sortedarrayusingselector: @selector (compare:)];

[@ "1" compare:@ "2"]; Sort by the incoming comparison method

Default order is from smaller to bigger

}

Nsarray Sort 2

For example, this is called (assuming the array contains a student object);

-(Nsarray *) Sortedarrayusingcomparator: (Comparator) cmptr

typedef nscomoarisionresult (^nscomparator) (id obj1,id obj2);

[Array sortedarrayusingcomparatorresult:^ (Student *s1,student *s2) {

return [S1.name Compare:s2.name;]

}];

Sort by name

Student.h

@interface Student:nsobject

@property (Nonatomic,retain) NSString *firstname;

@property (Nonatomic,retain) NSString *lastname;

+ (ID) studentwithfirstname: (NSString *) FirstName LastName: (*nsstring *) LastName;

Pass to @selector and return value must is Nscomparisionresult

-(Nscomparisionresult) Comparestudent: (Student *) Stu;

@end

Student.m

@implementation

+ (ID) studentwithfiestname: (NSString *) FirstName LastName: (*nsstring *) lastname{

Student *stu=[[[student Alloc]init]autorelease];

Because of static method + so we need to add autorelease.

Stu.lastname=lastname;

Stu.firstname=firstname;

return Stu;

}

We can store LastName Reult first

-(Nscomparisionresult) Comparestudent: (Student *) stu{

First sort with LastName then FirstName

Nscomparisionresult Result=[self.lastname Compare:stu.lastname];

If have same LastName then compare the FirstName

if (result==nsordersame) {

Result=[self.firstname Compare:stu.firstname];

}

return result;

}

}

-(void) dealloc{

[_FirstName release];

[_lastname release];

[Super Dealloc];

}

Rewrite Description Method

Yesi

-(NSString *) description{

return [NSString stringwithformat:@ "[%@%@]", self.lastname,self.firstname];

}

@end

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

#progma Mark Array Sort 2

#import "Student.h"

void ArraySort2 () {

Student *stu1=[student studentwithfirstname::@ "Yesi" lastname:@ "Huang"];

Student *stu2=[student studentwithfirstname::@ "Jujubee" lastname:@ "Sharma"];

Student *stu3=[student studentwithfirstname::@ "Hitu" lastname:@ "Sharma"];

Student *stu4=[student studentwithfirstname::@ "Madani" lastname:@ "Green"];

Nsarray *array=[nsarray Arraywithobjects:stu1,stu2,stu3,stu4,nil];

Now need to sort with FirstName then LastName

Nsarray *array2=[array sortedarrayusingselector: @selctor (comparestudent)];

}

Nsarray Sort 3 Use block (block completely not understand OK, roleback to see again)

#pragma mark Using block to sort

#import "Student.h"

void ArraySort3 () {

Student *stu1=[student studentwithfirstname::@ "Yesi" lastname:@ "Huang"];

Student *stu2=[student studentwithfirstname::@ "Jujubee" lastname:@ "Sharma"];

Student *stu3=[student studentwithfirstname::@ "Hitu" lastname:@ "Sharma"];

Student *stu4=[student studentwithfirstname::@ "Madani" lastname:@ "Green"];

Nsarray *array=[nsarray Arraywithobjects:stu1,stu2,stu3,stu4,nil];

Using a block to compare

Nsarray *araray2=[array sortedarrayusingcomparator:^nscomparisonresult (Student *obj1,student *obj2) {

Copy algorithm here...double Click can add a block quickly

First sort with LastName then FirstName

Nscomparisionresult Result=[obj1.lastname Compare:obj2.lastname];

If have same LastName then compare the FirstName

if (result==nsordersame) {

Result=[obj1.firstname Compare:obj2.firstname];

}

return result;

}];

NSLog (@ "array2:%@", array2);

}

32.17

Nsarray Sort 4 Student have a subclass book

Sort first with bookname then LastName then FirstName

#pragma mark Using block to sort

Book.h

@interface Book:nsobject

@property (Nonatomic,retain) NSString *name;

+ (ID) bookwithname: (NSString *) name;

@end

Book.m

@implementation Book

+ (ID) bookwithname: (NSString *name) {

Book *book=[[[book Alloc]init]autorelease];

Book.name=name;

return book;

}

-(void) dealloc{

[_name release];

[Super Dealloc];

}

@end

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

Student.h//add

@class book;

@property (nonatomic,retain) book *book;

+ (ID) studentwithfirstname: (NSString *) FirstName LastName: (NSString *) LastName BookName: (nstring *) bookname;

Student.m//add

+ (ID) studentwithfirstname: (NSString *) FirstName LastName: (NSString *) LastName BookName: (nstring *) bookname{

Student *stu=[student Studentwithfirstname:firstname Lastname:lastname];

Stu.book=[book bookwithname:bookname];//no Memory leak

return Stu;

}

Student.m//add

#import "Book.h"

-(void) dealloc{

[_FirstName release];

[_lastname release];

[_book release];

[Super Dealloc];

}

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

void ArrarSort4 () {

Student *stu1=[student studentwithfirstname::@ "Yesi" bookname:@ "Book1"];

Student *stu2=[student studentwithfirstname::@ "Jujubee" bookname:@ "Book2"];

Student *stu3=[student studentwithfirstname::@ "Hitu" bookname:@ "Book2"];

Student *stu4=[student studentwithfirstname::@ "Madani" bookname:@ "Book1"];

Nsarray *array=[nsarray Arraywithobjects:stu1,stu2,stu3,stu4,nil];

1 Sort by Title first

Nssortdescriptor *booknamedesc=[nssortdescriptor sortdescriptorwithkey:@ "Book.name" Ascending:YES];

2 again by surname

Nssortdescriptor *lastamedesc=[nssortdescriptor sortdescriptorwithkey:@ "LastName" Ascending:yes];

3 Finally by name

Nssortdescriptor *firstnamedesc=[nssortdescriptor sortdescriptorwithkey:@ "FirstName" Ascending:yes];

Nsarray Array2=[array Sortedarrayusingdescriptors:]

}

Nsarray derivation of a new collection

-(Nsarray *) Arraybyaddingobject: (ID) anobject

Add a new Array,and return a new Nsarray

-(Nsarray *) Arraybyaddingobjectsfromarray: (Nsarray *) Anotherarray

Add all the elements Inanother array and return a new Nsarray original array not change

-(Nsarray *) Subarraywithrange: (nsarray) Range

Load elements within range

#pragma derive a new array

void Arraynew () {

Nsarray *array=[nsarray arraywithobjects:@ "1", @ "2", nil];

Nsarray *array2=[array arraybyaddingobject:@ "3"];//merging arrays

The original array did not change, just the return array2 changed.

Nsarray *array3=[array arraybyaddingobjectsfromarray:[nsarray arraywithobject:@ "4", @ "5", NIL]];//4 elements

Nsarray *array4=[array arraywithobjects:@ "1", @ "2", @ "3", @ "4", nil];

Nsrange range= nsmakerange (n);

Nsarray *array5=[array4 Subarraywithrange:range];

}

Other method.

-(NSString) componentsjoinedbystring: (NSString *) seperator

Use a seperator to joint all the elements as a string

-(BOOL) write to File: (NSString *) path atomically: (bool) Use Auxiliaryfile

Tell a nsarray to persist in a file.

#pregma Mark Other method

void Arrayother () {

Nsarray *array=[array arraywithobjects:@ "1", @ "2", @ "3", @ "4", nil];

NSString *string=[array componentsjoinedbystring:@ ","];//1,2,3,4

NSString *[email protected] "/users/apple/desktop/array.xml";

[Arry writetofile:path atomically:yes];//create a XML file

Reading array contents from a file (file has strict formatting requirements)

NSString *[email protected] "/users/apple/desktop/array.txt";

Nsarray *array2=[nsarray Arraywithcontentsoffile:path];

}

Nsarray Sort 1

-(Nsarray *) Sortedarrayusingselector: (SEL) Comparator

Return a new sorted array, original array won't change

#pragma Mark ArraySort

void ArraySort1 () {

Nsarray *array=[array arraywithobjects:@ "2", @ "3", @ "1", @ "4", nil];

Nsarray *array2=[array sortedarrayusingselector: @selector (compare:)];

[@ "1" compare:@ "2"]; Sort by the incoming comparison method

Default order is from smaller to bigger

}

Nsarray Sort 2

For example, this is called (assuming the array contains a student object);

-(Nsarray *) Sortedarrayusingcomparator: (Comparator) cmptr

typedef nscomoarisionresult (^nscomparator) (id obj1,id obj2);

[Array sortedarrayusingcomparatorresult:^ (Student *s1,student *s2) {

return [S1.name Compare:s2.name;]

}];

Sort by name

Student.h

@interface Student:nsobject

@property (Nonatomic,retain) NSString *firstname;

@property (Nonatomic,retain) NSString *lastname;

+ (ID) studentwithfiestname: (NSString *) FirstName LastName: (*nsstring *) LastName;

Pass to @selector and return value must is Nscomparisionresult

-(Nscomparisionresult) Comparestudent: (Student *) Stu;

@end

Student.m

@implementation

+ (ID) studentwithfiestname: (NSString *) FirstName LastName: (*nsstring *) lastname{

Student *stu=[[[student Alloc]init]autorelease];

Because of static method + so we need to add autorelease.

Stu.lastname=lastname;

Stu.firstname=firstname;

return Stu;

}

We can store LastName Reult first

-(Nscomparisionresult) Comparestudent: (Student *) stu{

First sort with LastName then FirstName

Nscomparisionresult Result=[self.lastname Compare:stu.lastname];

If have same LastName then compare the FirstName

if (result==nsordersame) {

Result=[self.firstname Compare:stu.firstname];

}

return result;

}

}

-(void) dealloc{

[_FirstName release];

[_lastname release];

[Super Dealloc];

}

Rewrite Description Method

Yesi

-(NSString *) description{

return [NSString stringwithformat:@ "%@%@", Self.lastname,self.firstname];

}

@end

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

#progma Mark Array Sort 2

#import "Student.h"

void ArraySort2 () {

Student *stu1=[student studentwithfirstname::@ "Yesi"];

Student *stu2=[student studentwithfirstname::@ "Jujubee"];

Student *stu3=[student studentwithfirstname::@ "Hitu"];

Student *stu4=[student studentwithfirstname::@ "Madani"];

Nsarray *array=[nsarray Arraywithobjects:stu1,stu2,stu3,stu4,nil];

Now need to sort with FirstName then LastName

Nsarray *array2=[array sortedarrayusingselector: @selctor (comparestudent)];

}

Nsarray Sort 3 Use block (block completely not understand OK, roleback to see again)

#pragma mark Using block to sort

#import "Student.h"

void ArraySort3 () {

Student *stu1=[student studentwithfirstname::@ "Yesi"];

Student *stu2=[student studentwithfirstname::@ "Jujubee"];

Student *stu3=[student studentwithfirstname::@ "Hitu"];

Student *stu4=[student studentwithfirstname::@ "Madani"];

Nsarray *array=[nsarray Arraywithobjects:stu1,stu2,stu3,stu4,nil];

Using a block to compare

[Array Sortedarrayusingcomparator:^nscomparisonresult (Student *obj1,student *obj2) {//copy algorithm here...double Click can add a block quickly

First sort with LastName then FirstName

Nscomparisionresult Result=[obj1.lastname Compare:obj2.lastname];

If have same LastName then compare the FirstName

if (result==nsordersame) {

Result=[obj1.firstname Compare:obj2.firstname];

}

return result;

}];

}

Nsarray Sort 4 Student have a subclass book

Sort first with bookname then LastName then FirstName

#pragma mark Using block to sort

Book.h

@interface Book:nsobject

@property (Nonatomic,retain) NSString *name;

+ (ID) bookwithname: (NSString *) name;

@end

Book.m

@implementation Book

+ (ID) bookwithname: (NSString *name) {

Book *book=[[[book Alloc]init]autorelease];

Book.name=name;

return book;

}

-(void) dealloc{

[_name release];

[Super Dealloc];

}

@end

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

Student.h//add

@class book;

@property (nonatomic,retain) book *book;

+ (ID) studentwithfirstname: (NSString *) FirstName LastName: (NSString *) LastName BookName: (nstring *) bookname;

Student.m//add

+ (ID) studentwithfirstname: (NSString *) FirstName LastName: (NSString *) LastName BookName: (nstring *) bookname{

Student *stu=[student Studentwithfirstname:firstname Lastname:lastname];

Stu.book=[book bookwithname:bookname];//no Memory leak

return Stu;

}

Student.m//add

#import "Book.h"

-(void) dealloc{

[_FirstName release];

[_lastname release];

[_book release];

[Super Dealloc];

}

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

void ArrarSort4 () {

Student *stu1=[student studentwithfirstname::@ "Yesi" bookname:@ "Book1"];

Student *stu2=[student studentwithfirstname::@ "Jujubee" bookname:@ "Book2"];

Student *stu3=[student studentwithfirstname::@ "Hitu" bookname:@ "Book2"];

Student *stu4=[student studentwithfirstname::@ "Madani" bookname:@ "Book1"];

Nsarray *array=[nsarray Arraywithobjects:stu1,stu2,stu3,stu4,nil];

1 Sort by Title first

Nssortdescriptor *booknamedesc=[nssortdescriptor sortdescriptorwithkey:@ "Book.name" Ascending:YES];

2 again by surname

Nssortdescriptor *lastamedesc=[nssortdescriptor sortdescriptorwithkey:@ "LastName" Ascending:yes];

3 Finally by name

Nssortdescriptor *firstnamedesc=[nssortdescriptor sortdescriptorwithkey:@ "FirstName" Ascending:yes];

Nsarray Array2=[array Sortedarrayusingdescriptors:]

}

Sort of Nsarray