NSArray * arr1 = @[@"1 2 3",@"345",[NSNull null],@"789"];

NSArray * arr3 = [[NSArray alloc]initWithArray:arr1];

NSLog(@"arr3 == %@",arr3);

//將c數(shù)組轉(zhuǎn)換為oc數(shù)組對(duì)象

//oc不允許將nil插入到數(shù)組中,因?yàn)閚il作用是數(shù)組的結(jié)束標(biāo)記

NSString * carr[10] = {@"123",@"456",@"789"};

NSArray * arr4 = [[NSArray alloc]initWithObjects:carr count:2];

NSLog(@"arr4 == %@",arr4);

//獲取元素個(gè)數(shù)

NSUInteger count = [arr4 count];

NSLog(@"count = %ld",count);

//獲取指定下標(biāo)元素

NSLog(@"arr3.1 == %@",[arr3 objectAtIndex:1]);

//獲取第一個(gè)元素或者最后一個(gè)元素

id arrf = [arr3 firstObject];

id arrl = [arr3 lastObject];

NSLog(@"%@ %@",arrf,arrl);

//獲取子集

NSArray *arr2 = @[@"111", @"222", @"333", @"444", @"555", @"666"];

//取出連續(xù)范圍的元素作為子集內(nèi)容

NSArray *sub1 = [arr2 subarrayWithRange:NSMakeRange(1, 3)];

NSLog(@"sub1 = %@", sub1);

//獲取任意元素作為子集

//1.列出所需要元素的下標(biāo)清單

NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];

//1-1.將要獲取元素的下標(biāo)寫入清單

for (NSInteger i = 0; i < [arr2 count]; i++)

{

if (i % 2 != 1)

{

[indexs addIndex:i];

}

}

//2.將清單交給數(shù)組

//id obj =[arr2 objectAtIndex:0]; //獲取單個(gè)元素,返回單個(gè)元素

NSArray *sub2 = [arr2 objectsAtIndexes:indexs];//獲取下標(biāo)清單里的所有元素,返回一個(gè)元素集合(數(shù)組)

NSLog(@"sub2 = %@", sub2);

//獲取最長(zhǎng)字符串和最小字符串

//快速枚舉

NSArray *arr5 = @[@"123456789", @"22222", @"333", @"errr", @"444", @"5", @"666"];

NSInteger maxLength = [arr5[0] length];

NSInteger minLength = [arr5[0] length];

NSString *maxString = nil;

NSString *minString = nil;

for (id obj in arr5) {

if (maxLength <= [obj length]) {

maxLength = [obj length];

maxString = obj;

}

if (minLength >= [obj length]) {

minLength = [obj length];

minString = obj;

}

}

NSLog(@"maxString = %@, minString = %@",maxString,minString);

//創(chuàng)建可變數(shù)組對(duì)象

NSMutableArray *muarr1 = [[NSMutableArray alloc] initWithCapacity:30];

NSMutableArray *muarr2 = [NSMutableArray arrayWithCapacity:30];

//添加元素

[muarr1 addObject:@"123"];

[muarr1 addObject:@"456"];

[muarr2 addObjectsFromArray:muarr1];

[muarr2 addObject:@"789"];

[muarr2 addObject:@"45"];

[muarr2 addObject:@"789"];

[muarr2 addObject:@"789"];

NSLog(@"muarr1 = %@",muarr1);

NSLog(@"muarr2 = %@",muarr2);

//插入元素

//插入下標(biāo)的范圍: 0<=index<=count

[muarr1 insertObject:@"aaa" atIndex:1];

[muarr1 insertObject:@"bbb" atIndex:[muarr1 count]];

NSLog(@"muarr1 = %@",muarr1);

NSLog(@"刪除前的muarr2 == %@",muarr2);

//[muarr2 removeAllObjects];//刪除所有元素

//[muarr2 removeLastObject];//刪除最后一個(gè)元素

//[muarr2 removeObject:@"789"];//刪除指定對(duì)象，會(huì)將所有對(duì)象刪除

//[muarr2 removeObject:@"789" inRange:NSMakeRange(1, 2)];//刪除指定范圍中的指定對(duì)象

//[muarr2 removeObjectAtIndex:0];//刪除指定下標(biāo)的元素

//[muarr2 removeObjectsInRange:NSMakeRange(2, 2)];//刪除指定范圍中得元素

//[muarr2 removeObjectIdenticalTo:@"789"];

//[muarr2 removeObjectIdenticalTo:@"789" inRange:NSMakeRange(2, 1)];

//如果要?jiǎng)h除不連續(xù)的元素，則先把要?jiǎng)h除的元素放在一個(gè)清單中，然后再刪除該清單

//比如要?jiǎng)h下標(biāo)為偶數(shù)的

NSMutableIndexSet *indexs2 = [NSMutableIndexSet indexSet];

for (int i = 0; i < [muarr2 count]; i++) {

if (i % 2 == 0) {

[indexs2 addIndex:i];

}

}

//刪除清單中得元素

// [muarr2 removeObjectsAtIndexes:indexs2];

//替換指定下標(biāo)的值

//[muarr2 replaceObjectAtIndex:2 withObject:@"aaa"];

//NSArray *arr = @[@"qqqq",@"www",@"ee"];//注意數(shù)組越界

//[muarr2 replaceObjectsAtIndexes:indexs2 withObjects:arr];

//[muarr2 replaceObjectsInRange:NSMakeRange(1, 3) withObjectsFromArray:arr];// qq, qq, ww, ee, ee,在指定范圍內(nèi)，修改數(shù)組中得內(nèi)容。

//交換數(shù)組中得內(nèi)容

// [muarr2 exchangeObjectAtIndex:1 withObjectAtIndex:3];

//用oc對(duì)c語言中得數(shù)組進(jìn)行排序

for (int i = 0; i < [muarr2 count]; ++i) {

for (int j = i + 1; j < [muarr2 count]; ++j) {

if ([muarr2[i] length] < [muarr2[j] length]) {

[muarr2 exchangeObjectAtIndex:i withObjectAtIndex:j];

}

}

}

NSLog(@"刪除后的muarr2 == %@",muarr2);

排序

? ? NSArray * arr1 = @[@"1",@"3",@"2",@"9",@"5",@"4"];

? ? NSMutableArray * arr = [[NSMutableArray alloc]initWithArray:arr1];

? ?for (int i = 0; i<[arr count]; ++i) {

? ? ? ? for (int j = i + 1; j<[arr count]; ++j) {

? ? ? ? ? ? if ([arr[i] floatValue] > [arr[j] floatValue]) {

? ? ? ? ? ? ? ? [arr exchangeObjectAtIndex:i withObjectAtIndex:j];

? ? ? ? ? ? }

? ? ? ? }

? ? }

?// ?NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];

//? ? NSInteger num = [arr count]/2;

//? ? [indexs addIndex:num];

//? ? NSArray * sub = [arr objectsAtIndexes:indexs];

//? ? NSLog(@"%@",sub[0]);