NSString *string2 = @"one";
//创建数组
NSArray *array1 = [NSArray arrayWithObjects:string1,string2,nil];
NSArray *array2 = [NSArray arrayWithArray:array1];
//创建数组只包含已有数组的一部分
NSRange range = NSMakeRange(0, 2);
NSArray *subArray = [array1 subarrayWithRange:range];
//array的长度
int arrayLength = [array1 count];
//访问数组中特定位置的一个对象
NSString *string = [array1 objectAtIndex:0];
//是否包含指定对象
BOOL isInArray = [array1 containsObject:string1];
//对象在数组中的位置
int index = [array1 indexOfObject:string1];
//遍历一个数组中的值
for(NSString *obj in array1)
{
NSLog(@"%@",obj);
}
//反向遍历一个数组的值
for(NSString *objfan in [array1reverseObjectEnumerator])
{
NSLog(@"%@",objfan);
}
//对字符串的重新排序(有点问题)
//[array1 sortUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
//NSLog(@"array1 = %@",array1);
//创建动态数组
NSMutableArray *myarray = [[NSMutableArray alloc]initWithObjects:string1,string2, nil];
NSString *string3 = @"Three";
//向动态数组中添加
[myarray addObject:string3];
[myarray addObject:string2];
[myarray insertObject:string3 atIndex:0];
[myarray insertObject:string2 atIndex:1];
//替换
[myarray replaceObjectAtIndex:1withObject:string3];
//删除
[myarray removeObject:string3];
//删除特定位置对象
[myarray removeObjectAtIndex:0];
//删除几个对象
[myarray removeObjectsInRange:range];
//删除所有对象
[myarray removeAllObjects];
#pragma mark 数组的内存管理
void arrayMemory() {
// 1
Student *stu1 = [[Student alloc] init];
Student *stu2 = [[Student alloc] init];
Student *stu3 = [[Student alloc] init];
NSLog(@"stu1:%zi", [stu1 retainCount]);
// 当把一个对象塞进数组中时,这个对象的计数器会加1,也就是说数组会对它做一次retain操作
// 2
NSArray *array = [[NSArray alloc] initWithObjects:stu1, stu2, stu3, nil];
NSLog(@"stu1:%zi", [stu1 retainCount]);
NSLog(@"count=%zi", array.count);
// 1
[stu1 release];
[stu2 release];
[stu3 release];
// 数组被销毁的时候,会对内部的所有元素都做一次release操作
// 0
[array release];
}
#pragma mark 给数组里面的元素发送消息
void arrayMessage() {
Student *stu1 = [Student student];
Student *stu2 = [Student student];
Student *stu3 = [Student student];
NSArray *array = [NSArray arrayWithObjects:stu1, stu2, stu3, nil];
// 让数组里面的所有对象都调用test方法
// [array makeObjectsPerformSelector:@selector(test)];
[array makeObjectsPerformSelector:@selector(test2:) withObject:@"123"];
}
#pragma mark 派生出新的数组
void arrayNew() {
NSArray *array = [NSArray arrayWithObjects:@"1", @"2", nil];
NSArray *array2 = [array arrayByAddingObject:@"3"];
NSArray *array3 = [array arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:@"4", @"5", nil]];
NSLog(@"array:%@", array);
NSLog(@"array2:%@", array2);
NSLog(@"array3:%@", array3);
NSArray *array4 = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil];
NSRange range = NSMakeRange(1, 2);
NSArray *array5 = [array4 subarrayWithRange:range];
NSLog(@"array5:%@", array5);
}
#pragma mark 数组的其他用法
void arrayOther() {
NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil];
// 1-2-3-4
// 利用分隔符-拼接所有的数组元素
NSString *str = [array componentsJoinedByString:@"-"];
NSLog(@"%@", str);
// 将一个数组写入文件(生成的是一个xml文件)
NSString *path = @"/Users/apple/Desktop/array.xml";
[array writeToFile:path atomically:YES];
path = @"/Users/apple/Desktop/array.txt";
// 从文件中读取数组内容(文件有严格的格式要求)
NSArray *array2 = [NSArray arrayWithContentsOfFile:path];
NSLog(@"array2:%@", array2);
}
#pragma mark 数组排序1
void arraySort1() {
NSArray *array = [NSArray arrayWithObjects:@"2", @"3", @"1", @"4", nil];
// 返回一个排好序的数组,原来数组的元素顺序不会改变
// 指定元素的比较方法:compare:
NSArray *array2 = [array sortedArrayUsingSelector:@selector(compare:)];
NSLog(@"array2:%@", array2);
}
#pragma mark 数组排序2
void arraySort2() {
Student *stu1 = [Student studentWithFirstname:@"MingJie" lastname:@"Li"];
Student *stu2 = [Student studentWithFirstname:@"LongHu" lastname:@"Huang"];
Student *stu3 = [Student studentWithFirstname:@"LianJie" lastname:@"Li"];
Student *stu4 = [Student studentWithFirstname:@"Jian" lastname:@"Xiao"];
NSArray *array = [NSArray arrayWithObjects:stu1,stu2,stu3, stu4, nil];
// 指定排序的比较方法
NSArray *array2 = [array sortedArrayUsingSelector:@selector(compareStudent:)];
NSLog(@"array2:%@", array2);
}
#pragma mark 数组排序3
void arraySort3() {
Student *stu1 = [Student studentWithFirstname:@"MingJie" lastname:@"Li"];
Student *stu2 = [Student studentWithFirstname:@"LongHu" lastname:@"Huang"];
Student *stu3 = [Student studentWithFirstname:@"LianJie" lastname:@"Li"];
Student *stu4 = [Student studentWithFirstname:@"Jian" lastname:@"Xiao"];
NSArray *array = [NSArray arrayWithObjects:stu1,stu2,stu3, stu4, nil];
// 利用block进行排序
NSArray *array2 = [array sortedArrayUsingComparator:
^NSComparisonResult(Student *obj1, Student *obj2) {
// 先按照姓排序
NSComparisonResult result = [obj1.lastname compare:obj2.lastname];
// 如果有相同的姓,就比较名字
if (result == NSOrderedSame) {
result = [obj1.firstname compare:obj2.firstname];
}
return result;
}];
NSLog(@"array2:%@", array2);
}
#pragma mark 数组排序4-高级排序
void arraySort4() {
Student *stu1 = [Student studentWithFirstname:@"MingJie" lastname:@"Li" bookName:@"book1"];
Student *stu2 = [Student studentWithFirstname:@"LongHu" lastname:@"Huang" bookName:@"book2"];
Student *stu3 = [Student studentWithFirstname:@"LianJie" lastname:@"Li" bookName:@"book2"];
Student *stu4 = [Student studentWithFirstname:@"Jian" lastname:@"Xiao" bookName:@"book1"];
NSArray *array = [NSArray arrayWithObjects:stu1,stu2,stu3, stu4, nil];
// 1.先按照书名进行排序
// 这里的key写的是@property的名称
NSSortDescriptor *bookNameDesc = [NSSortDescriptor sortDescriptorWithKey:@"book.name" ascending:YES];
// 2.再按照姓进行排序
NSSortDescriptor *lastnameDesc = [NSSortDescriptor sortDescriptorWithKey:@"lastname" ascending:YES];
// 3.再按照名进行排序
NSSortDescriptor *firstnameDesc = [NSSortDescriptor sortDescriptorWithKey:@"firstname" ascending:YES];
// 按顺序添加排序描述器
NSArray *descs = [NSArray arrayWithObjects:bookNameDesc, lastnameDesc, firstnameDesc, nil];
NSArray *array2 = [array sortedArrayUsingDescriptors:descs];
NSLog(@"array2:%@", array2);
}