objective-c 语言 数组遍历的4种方式

01

#import
"Blog.h"

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@implementation
Blog

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04

+(Blog
*)blog{

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Blog
* blog = [[Blog alloc] init];

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return

blog;

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}

08

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-(Blog
*)setBlogTitle:(NSString *)title andContent:(NSString *)content{

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_title
= title;

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_content
= content;

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return

self;

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}

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-(NSString
*)description{

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return

[NSString
stringWithFormat:@

"blog
: title is \"%@\" , and content is \"%@\""

,
_title,_content ];

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}

18

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-(

void

)dealloc{

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NSLog(@

"%@被销毁了"

,self.title);

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}

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@end

01

#pragma
mark Array数组的四种遍历方法

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void

testArray(){

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Blog
*blog1 = [[Blog blog] setBlogTitle:@

"Love"

andContent:@

"I
love you"

];

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Blog
*blog2 = [[Blog blog] setBlogTitle:@

"Friendship"

andContent:@

"you
are my best friend"

];

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NSArray
*array = [NSArray arrayWithObjects:@

"hello"

,@

"world"

,blog1,blog2,
nil];

06

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//第一种遍历：普通for循环

08

long

int

count
= [array count];

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for

(

int

i
= 0 ; i < count; i++) {

10

NSLog(@

"1遍历array:
%zi-->%@"

,i,[array
objectAtIndex:i]);

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}

12

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//第二种遍历：快速for循环,需要有外变量i

14

int

i
= 0;

15

for

(id
obj in array) {

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NSLog(@

"2遍历array：%zi-->%@"

,i,[array
objectAtIndex:i]);

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i++;

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}

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//第三种遍历：OC自带方法enumerateObjectsUsingBlock:

21

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//默认为正序遍历

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[array
enumerateObjectsUsingBlock:^(id obj, NSUInteger idx,

BOOL

*stop)
{

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NSLog(@

"3遍历array：%zi-->%@"

,idx,obj);

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}];

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//NSEnumerationReverse参数为倒序遍历

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[array
enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(id obj, NSUInteger idx,

BOOL

*stop)
{

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NSLog(@

"4倒序遍历array：%zi-->%@"

,idx,obj);

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}];

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//第四种遍历：利用枚举

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NSEnumerator
*en = [array objectEnumerator];

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id
obj;

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int

j
= 0 ;

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while

(obj
= [en nextObject]) {

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NSLog(@

"5遍历array：%d-->%@"

,j,obj);

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j++;

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}

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}

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int

main(

int

argc,

const

char

*
argv[])

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{

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@autoreleasepool
{

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testArray();

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}

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return

0;

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}