#import <Foundation/Foundation.h>

//排序算法,应用于 NSArray *arr=[arrs1 sortedArrayUsingFunction:sortByID context:nil];排序

NSInteger sortByID(id obj1, id obj2, void *context){

NSString *str1 =(NSString*) obj1;

NSString *str2 =(NSString *) obj2;

if (str1.length < str2.length) {

return NSOrderedDescending;

}

else if(str1.length == str2.length)

{

return NSOrderedSame;

}

return NSOrderedAscending;

}

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

@autoreleasepool {

//数组只能存储oc对象,NSArray一旦创建不能修改

NSArray *arrs0=@[@"123",@"456",@"789"];

//初始化数组的一种奇葩

NSArray *arrs1=[NSArray arrayWithArray:arrs0];

//1.获取数组中的元素对象

id need=[arrs1 objectAtIndex:1];//取出索引位置中的对象

id nn=[arrs1 objectAtIndexedSubscript:1];

NSLog(@"need=%@",need);

//2.元素个数

int t=[arrs1 count];

//3.判断是否包含

bool isYes=[arrs1 containsObject:@"123"];

//4.取得数组中第一个和最后一个元素

need= [arrs1 firstObject];

need=[arrs1 lastObject];

//5.添加元素,返回另一个数组

arrs0=[arrs1 arrayByAddingObject:@"000"];

//6.合并两个数组

arrs0=[arrs1 arrayByAddingObjectsFromArray:arrs1];

NSLog(@"%@",arrs0);

//7.取得数组一定范围内的数据

arrs0=[arrs1 subarrayWithRange:NSMakeRange(1, 1)];

NSLog(@"%ld",[arrs0 count]);

//8.判断是否相等

isYes=[arrs0 isEqualToArray:arrs1];

//9.返回元素的位置

int tt=[arrs0 indexOfObject:@"123"];

NSLog(@"%d",tt);

tt=[arrs0 indexOfObjectIdenticalTo:@"123"];

//10.数组与字符串的转换

NSString *sss=[arrs1 componentsJoinedByString:@"-"];

//11.字符串与数组转换

NSArray *array=[sss componentsSeparatedByString:@"-"];

NSLog(@"%@",sss);

NSLog(@"%@",array);

//sortedArrayHint:不知道怎么用的

//int num=[array sortedArrayHint];

//NSLog(@"%ld",num);

//12.写入文件,写入url

[arrs1 writeToFile:@"/users/tang/desktop/array.plist" atomically:YES];

NSArray *arrfile=[NSArray arrayWithContentsOfFile:@"/users/tang/desktop/array.plist"];

NSLog(@"%@",arrfile);

//13.数组的遍历 还有两种

[arrs1 enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

NSLog(@"%d,%@",idx,obj);

if(idx==1)

{

*stop=YES;

}

}];

//14.正向遍历

NSEnumerator *dfd=[arrs1 objectEnumerator];

for (id dd in dfd) {

NSLog(@"%@",dd);

}

//15.反向遍历

dfd=[arrs1 reverseObjectEnumerator];

for (id dd in dfd) {

NSLog(@"%@",dd);

}

//16用自己写的函数实现数组的排序

NSArray *arr=[arrs1 sortedArrayUsingFunction:sortByID context:nil];

// NSLog(@"%ld",NSNotFound);

}

return 0;

}