OC数组相关的基础操作
objective-c系列-NSMutableArray,objective-c
NSArray * arr1 = @[@"1 2 3",@"345",[NSNull null],@"789"];
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NSArray * arr3 = [[NSArray alloc]initWithArray:arr1];
// 可变数组构造方法
NSLog(@"arr3 == %@",arr3);
// 下边两句的定义都是不可变的
//将c数组转换为oc数组对象
// NSMutableArray *marray1 = [[ NSArray alloc]init];
//oc不允许将nil插入到数组中,因为nil作用是数组的结束标记
// NSMutableArray * marray1 = @[@"xx",@"yy"];
NSString * carr[10] = {@"123",@"456",@"789"};
NSArray * arr4 = [[NSArray alloc]initWithObjects:carr count:2];
//默认数组没有元素
NSLog(@"arr4 == %@",arr4);
NSMutableArray * marray1 = [[ NSMutableArray alloc]init];
//获取元素个数
NSMutableArray * marray = [NSMutableArray array];
NSUInteger count = [arr4 count];
NSMutableArray * marray2 = [[ NSMutableArray alloc]initWithArray:@[@"1",@"2"]];
NSLog(@"count = %ld",count);
NSMutableArray * marray3 = [[NSMutableArray alloc]initWithObjects:@"one",@"two",@"three", nil];
//获取指定下标元素
NSLog(@"arr3.1 == %@",[arr3 objectAtIndex:1]);
id objs[5] ={@"123",@"456",@"789",@"abc",@"def"};
//获取第一个元素或者最后一个元素
// objs 的类型为: id [5];
id arrf = [arr3 firstObject];
// 因为objs是数组名,即首元素的地址,又因为首元素的类型为id;
id arrl = [arr3 lastObject];
// 所以: objs的类型为: id *
NSLog(@"%@ %@",arrf,arrl);
//获取子集
NSMutableArray * marray4 = [[NSMutableArray alloc]initWithObjects: objs count:3];
NSArray *arr2 = @[@"111", @"222", @"333", @"444", @"555", @"666"];
NSLog(@"marray4: %@", marray4);
//取出连续范围的元素作为子集内容
NSArray *sub1 = [arr2 subarrayWithRange:NSMakeRange(1, 3)];
// 开辟80个字节的动态内存,给memory,
NSLog(@"sub1 = %@", sub1);
// 即memory指向了80个字节的合法内存
//获取任意元素作为子集
id * memory = (__bridge id *)malloc(80);
//1.列出所需要元素的下标清单
memory[0]=@"mem1";
NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];
memory[1]=@"mem2";
//1-1.将要获取元素的下标写入清单
memory[2]=@"mem3";
for (NSInteger i = 0; i < [arr2 count]; i++)
memory[3]=@"mem4";
{
memory[4]=@"mem5";
if (i % 2 != 1)
NSMutableArray * marray5 = [[ NSMutableArray alloc]initWithObjects:memory count:3];
{
NSLog(@"marray5: %@", marray5);
[indexs addIndex:i];
}
//构造一个可变数组,初始给它10个元素空间, 但没有元素
}
NSMutableArray * marray6 = [[ NSMutableArray alloc]initWithCapacity:10];
//2.将清单交给数组
//注意: marray6还是一个空数组,即没有元素存在
//id obj =[arr2 objectAtIndex:0]; //获取单个元素,返回单个元素
NSLog(@"marray6:%@", marray6);
NSArray *sub2 = [arr2 objectsAtIndexes:indexs];//获取下标清单里的所有元素,返回一个元素集合(数组)
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NSLog(@"sub2 = %@", sub2);
//给数组添加元素
//获取最长字符串和最小字符串
// add insert
//快速枚举
NSMutableArray * array = [[ NSMutableArray alloc]init];
NSArray *arr5 = @[@"123456789", @"22222", @"333", @"errr", @"444", @"5", @"666"];
//尾部追加一个元素
NSInteger maxLength = [arr5[0] length];
[array addObject:@"theFirstObject"];
NSInteger minLength = [arr5[0] length];
NSLog(@"第一次调 addObject: array: %@",array);
NSString *maxString = nil;
NSString *minString = nil;
[array addObject:@"theSecondObject"];
for (id obj in arr5) {
NSLog(@"第二次调 addObject: array: %@", array);
if (maxLength <= [obj length]) {
maxLength = [obj length];
//尾部拼接一个数组
maxString = obj;
[array addObjectsFromArray:@[@"add1",@"add2"]];
}
NSLog(@"第一次调 addObjectsFromArray: array: %@", array);
if (minLength >= [obj length]) {
minLength = [obj length];
//结果说明 addObject是往数组的尾部追加元素
minString = obj;
[array insertObject:@"theInsertObject" atIndex:1];
}
NSLog(@"第一次调 insertObject: array: %@", array);
}
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NSLog(@"maxString = %@, minString = %@",maxString,minString);
//删除数组中的元素
//创建可变数组对象
NSMutableArray * array = [[ NSMutableArray alloc]initWithArray:@[@"1",@"2",@"3",@"4",@"5",@"6",@"1",@"1" ]];
NSMutableArray *muarr1 = [[NSMutableArray alloc] initWithCapacity:30];
NSLog(@"array: %@", array);
NSMutableArray *muarr2 = [NSMutableArray arrayWithCapacity:30];
// remove
//添加元素
//删除这个对象在数组中的所有出现的地方
[muarr1 addObject:@"123"];
[array removeObject:@"1"];
[muarr1 addObject:@"456"];
NSLog(@"第一次调 removeObject: array: %@",array);
[muarr2 addObjectsFromArray:muarr1];
[muarr2 addObject:@"789"];
//删除最后一个元素
[muarr2 addObject:@"45"];
[array removeLastObject];
[muarr2 addObject:@"789"];
//删除指下定标的元素
[muarr2 addObject:@"789"];
[array removeObjectAtIndex:0];
NSLog(@"muarr1 = %@",muarr1);
//删除所有的元素
NSLog(@"muarr2 = %@",muarr2);
[array removeAllObjects];
//插入元素
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//插入下标的范围: 0<=index<=count
//重置数组,替换数组的某个下标的元素
[muarr1 insertObject:@"aaa" atIndex:1];
NSMutableArray * array = [[ NSMutableArray alloc]initWithArray:@[@"abc",@"def",@"ghi"]];
[muarr1 insertObject:@"bbb" atIndex:[muarr1 count]];
NSLog(@"muarr1 = %@",muarr1);
NSLog(@"原始数组: array: %@",array);
NSLog(@"删除前的muarr2 == %@",muarr2);
NSArray * newArray = @[@"123",@"456",@"789"];
//[muarr2 removeAllObjects];//删除所有元素
[array replaceObjectsInRange:NSMakeRange(0, [array count]) withObjectsFromArray:newArray];
//[muarr2 removeLastObject];//删除最后一个元素
NSLog(@"全部元素被替换后的数组: array: %@",array);
//[muarr2 removeObject:@"789"];//删除指定对象,会将所有对象删除
//[muarr2 removeObject:@"789" inRange:NSMakeRange(1, 2)];//删除指定范围中的指定对象
[array replaceObjectAtIndex:1 withObject:@"[theFisrtReplaceObject]"];
//[muarr2 removeObjectAtIndex:0];//删除指定下标的元素
NSLog(@"替换某一个下标的元素:array: %@",array);
//[muarr2 removeObjectsInRange:NSMakeRange(2, 2)];//删除指定范围中得元素
NSLog(@"新替换后的元素为: %@", [array objectAtIndex:1]);
//[muarr2 removeObjectIdenticalTo:@"789"];
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//[muarr2 removeObjectIdenticalTo:@"789" inRange:NSMakeRange(2, 1)];
//数组对象的其它常用方法
//如果要删除不连续的元素,则先把要删除的元素放在一个清单中,然后再删除该清单
NSArray * array = @[@"one",@"two",@"three"];
//比如要删下标为偶数的
//获取数组的首元素
NSMutableIndexSet *indexs2 = [NSMutableIndexSet indexSet];
id obj1 = [array firstObject];
for (int i = 0; i < [muarr2 count]; i++) {
NSLog(@"obj1: %@", obj1);
if (i % 2 == 0) {
//获取数组的尾元素
[indexs2 addIndex:i];
id obj2 = [array lastObject];
}
NSLog(@"obj2: %@", obj2);
}
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//删除清单中得元素
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******************************************** // 可变数组构造方法 // 下边两句的定义都是不可变的 // NSMutableArray...
// [muarr2 removeObjectsAtIndexes:indexs2];
//替换指定下标的值
//[muarr2 replaceObjectAtIndex:2 withObject:@"aaa"];
//NSArray *arr = @[@"qqqq",@"www",@"ee"];//注意数组越界
//[muarr2 replaceObjectsAtIndexes:indexs2 withObjects:arr];
//[muarr2 replaceObjectsInRange:NSMakeRange(1, 3) withObjectsFromArray:arr];// qq, qq, ww, ee, ee,在指定范围内,修改数组中得内容。
//交换数组中得内容
// [muarr2 exchangeObjectAtIndex:1 withObjectAtIndex:3];
//用oc对c语言中得数组进行排序
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(@"删除后的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]);
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