[OC Learning note] Array traversal and sorting

1         //Array Traversal (example of a variable group)2         //For traversal3Nsmutablearray *AA =[Nsmutablearray array];4[AA addobjectsfromarray:@[@"SS",@"DDD",@"Sad"]];5          for(inti =0; i < Aa.count; i++) {6NSLog (@"%@", [AA objectatindex:i]);7         }8         //Fast Traversal9          for(IDObjinchAA) {TenNSLog (@"%@", obj); One         } A         //code block Traversal -         //obj is the object idx is subscript stop is a stop flag -[AA enumerateobjectsusingblock:^ (IDobj, Nsuinteger idx, BOOL *stop) { theNSLog (@"%@", obj); -NSLog (@"%@", [AA objectatindex:idx]); -         }]; -         //iterator Traversal +         //storing array elements in iterators -Nsenumerator *en =[AA Objectenumerator]; +         IDobj = nil;//create an object to accept the returned object A          while(obj =[en nextobject]) { atNSLog (@"%@", obj); -         } -         //Reverse iterator Traversal -Nsenumerator *en1 =[AA Reverseobjectenumerator]; -         IDObj1 =Nil; -          while(Obj1 =[En1 Nextobject]) { inNSLog (@"%@", obj1); -         } to          +          -         //Sort (Variable group example) the         //variable array sorting method no return value the order of the immutable group has a return value *         //Selector Sort $         //Compare method is limited to comparing elements is a character, if there is another comparison please write the comparison method return value (Nscomparisonresult)Panax Notoginseng [AA sortusingselector: @selector (compare:)]; -         //code block ordering the         //write the judging method according to the actual situation +[AA Sortusingcomparator:^nscomparisonresult (IDObj1,IDobj2) { A             return[Obj1 compare:obj2]; the         }]; +         //Compare Descriptor Ordering -         //ordering more than one condition is convenient $Person *P1 =[[Person alloc]init]; $P1.name =@"SS"; -P1.age =@" -"; -          thePerson *P2 =[[Person alloc]init]; -P2.name =@"DD";WuyiP2.age =@" -"; the          -Person *P3 =[[Person alloc]init]; WuP3.name =@"hh"; -P3.age =@" A"; About          $Person *P4 =[[Person alloc]init]; -P4.name =@"hh"; -P4.age =@" +"; -Nsmutablearray *sss =[Nsmutablearray Arraywithobjects:p1,p2,p3,p4,nil]; ANssortdescriptor *sort1 = [Nssortdescriptor sortdescriptorwithkey:@"name"Ascending:yes]; +Nssortdescriptor *sort2 = [Nssortdescriptor sortdescriptorwithkey:@" Age"Ascending:yes]; theNsarray *s =@[sort1,sort2]; - [SSS sortusingdescriptors:s]; $NSLog (@"%@", SSS);

Person.h

1 #import <Foundation/Foundation.h>23@interface  person:nsobject 4 @property (nonatomic,strong) NSString *name; 5 @property (nonatomic,strong) NSString * age; 6 @end

Person.m

1 #import "Person.h"2 3 @implementation Person4-(NSString *) Description5 {6     return[NSString stringWithFormat:@"%@ %@", _name,_age];7 }8 @end

Run result Analysis:

 -- .- on  -:Panax Notoginseng:55.984array[2030:140148] SS -- .- on  -:Panax Notoginseng:55.985array[2030:140148] DDD -- .- on  -:Panax Notoginseng:55.985array[2030:140148] Sad -- .- on  -:Panax Notoginseng:55.986array[2030:140148] SS -- .- on  -:Panax Notoginseng:55.986array[2030:140148] DDD -- .- on  -:Panax Notoginseng:55.986array[2030:140148] Sad -- .- on  -:Panax Notoginseng:55.986array[2030:140148] SS -- .- on  -:Panax Notoginseng:55.986array[2030:140148] SS -- .- on  -:Panax Notoginseng:55.986array[2030:140148] DDD -- .- on  -:Panax Notoginseng:55.987array[2030:140148] DDD -- .- on  -:Panax Notoginseng:55.987array[2030:140148] Sad -- .- on  -:Panax Notoginseng:55.987array[2030:140148] Sad -- .- on  -:Panax Notoginseng:55.992array[2030:140148] SS -- .- on  -:Panax Notoginseng:55.992array[2030:140148] DDD -- .- on  -:Panax Notoginseng:55.992array[2030:140148] Sad -- .- on  -:Panax Notoginseng:55.992array[2030:140148] Sad -- .- on  -:Panax Notoginseng:55.992array[2030:140148] DDD -- .- on  -:Panax Notoginseng:55.993array[2030:140148] SS -- .- on  -:Panax Notoginseng:55.993array[2030:140148] (    "DD",    "hh",    "hh",    "SS")

[OC Learning note] Array traversal and sorting