ios 数组处理记录

//创建一个数组

NSArray*myArray;

NSValue*aValue = [NSNumbernumberWithInt:5];

NSString*aString =@"nihoa";

// NSString *aString = [NSString stringWithFormat:@"nihao"];

myArray = [NSArrayarrayWithObjects:aValue, aString,nil];//用便利构造器

NSLog(@"%@",myArray);

NSArray*arr = [[NSArrayalloc]initWithObjects:@"one",@"two",nil];//用alloc+init

NSLog(@"%@",arr);

//查询数组中是否有某个元素返回值是BOOL类型

if([arrcontainsObject:@"one"])

NSLog(@"YES");

else

NSLog(@"NO");

//元素个数

NSLog(@"%lu",[arrcount]);

[arrrelease];

//检索元素 并存放在C语言的数组中

NSArray*arr1 = [[NSArrayalloc]initWithObjects:@"one",@"two",@"three",@"four",nil];

id*objects;

NSUIntegercount = [arr1count];

objects =malloc(sizeof(id) * count);//objects数组名

[arr1getObjects:objects];

for(NSUIntegeri =0; i < count; i++) {

NSLog(@"object at index %lu: %@", i, objects[i]);

}

free(objects);

//检索某个下标的元素

NSLog(@"%@",[arr1objectAtIndex:0]);

//检索某个元素的下标

NSLog(@"%lu",[arr1indexOfObject:@"two"]);

NSLog(@"%lu",[arr1indexOfObject:@"two"inRange:NSMakeRange(0,3)]);

//在数组中增加元素

NSArray*arr2 = [arr1arrayByAddingObject:@"tiandadida"];

NSLog(@"%@",arr2);

[arr1release];

//排序

NSArray*arrnumber= [[NSArrayalloc]initWithObjects:@"nihao",@"wo",@"helloword",@"zhonggu",nil];

NSArray*te = [arrnumbersortedArrayUsingComparator: ^(NSString*s,NSString*s2){

if(s.length< s2.length){

returnNSOrderedDescending;

}

if(s.length> s2.length){

returnNSOrderedAscending;

}

// NSLog(@"...........................");

returnNSOrderedSame;

}];

NSLog(@"te=%@.",te);

//firstObjectCommonWithArray的用法

NSArray*arrnum= [[NSArrayalloc]initWithObjects:@"haoma",@"wo",@"helloword",@"zhongguo",nil];

NSLog(@"%@",[arrnumberfirstObjectCommonWithArray:arrnum]);

//快速枚举

NSArray*ar = [NSArrayarrayWithObjects:@"one",@"two",@"three",nil];

for(NSString*elementinar) {

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

}

//lastobject

NSLog(@"%@",[arlastObject]);

//把数组元素(字符串),连接起来.

NSString*string = [arcomponentsJoinedByString:@"->"];

NSLog(@"%@",string);

//某个范围的子串

NSRangetheRange;

theRange.location=0;//range的起点

theRange.length= [arcount] /2;//range的长度

NSArray*halfArray = [arsubarrayWithRange:theRange];

NSLog(@"%@",halfArray);

//description Returns a string that represents the contents of the array, formatted as a property list.

NSString*test = [ardescription];

NSLog(@"%@",test);

}