OC复习
// // main.m // oc复习 // // Created by User on 3/10/13. // Copyright (c) 2013 User. All rights reserved. // #import <Foundation/Foundation.h> #import "Student.h" //创建一个数组 void arrayCreate() { // 创建一个空的数组 NSArray *array = [NSArray array]; // 创建有1个元素的数组 array = [NSArray arrayWithObject:@"123"]; // 创建有多个元素的数组 array = [NSArray arrayWithObjects:@"a", @"b", @"c", nil]; // 数组的元素 int count = [array count]; // count = array.count; NSLog(@"%i", count); } #pragma mark 数组的简单使用 void arrayUse() { NSArray *array = [NSArray arrayWithObjects:@"a", @"b", @"c", nil]; // 判断是否包含了某个元素 if ([array containsObject:@"a"]) { NSLog(@"包含了字符串a"); } //得到数组的最后一个元素 NSString *last = [array lastObject]; NSLog(@"last=%@", last); //得到索引为1的元素 NSString *str = [array objectAtIndex:1]; NSLog(@"%@", str); //得到元素c的索引 int index = [array indexOfObject:@"c"]; NSLog(@"index=%i", index); } #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]); // 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]; } //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"]; } //遍历数组1 void arrayFor1() { Student *stu1 = [Student student]; NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil]; int count = array.count; for (int i = 0; i<count; i++) { // id == void * id obj = [array objectAtIndex:i]; NSLog(@"%i-%@", i, obj); } } //遍历数组2 void arrayFor2() { Student *stu1 = [Student student]; NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil]; // 快速遍历 int i =0; for (id obj in array) { NSLog(@"%i-%@", i, obj); i++; } } //遍历数组3 void arrayFor3() { Student *stu1 = [Student student]; NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil]; [array enumerateObjectsUsingBlock: ^(id obj, NSUInteger idx, BOOL *stop) { NSLog(@"%i-%@", idx, obj); // 如果索引为1,就停止遍历 if (idx == 1) { // 利用指针修改外面BOOL变量的值 *stop = YES; } }]; } //遍历数组4 void arrayFor4() { Student *stu1 = [Student student]; NSArray *array = [NSArray arrayWithObjects:stu1, @"1", @"2", @"3", nil]; // 获取数组的迭代器 // NSEnumerator *enumerator = [array objectEnumerator]; // 反序迭代器(从尾部开始遍历元素) NSEnumerator *enumerator = [array reverseObjectEnumerator]; // allObjects是取出没有被遍历过的对象 NSArray *array2 = [enumerator allObjects]; NSLog(@"array2:%@", array2); // 获取下一个需要遍历的元素 id obj = nil; while (obj = [enumerator nextObject]) { NSLog(@"obj=%@", obj); } } //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);//1,2 NSLog(@"array2:%@", array2);//1,2,3 NSLog(@"array3:%@", array3);//1,2,4,5 NSArray *array4 = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", nil]; NSRange range = NSMakeRange(1, 2); NSArray *array5 = [array4 subarrayWithRange:range]; NSLog(@"array5:%@", array5);//2,3 } #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/user/Desktop/array.xml"; [array writeToFile:path atomically:YES]; // 从文件中读取数组内容(文件有严格的格式要求) path = @"/Users/user/Desktop/array.xml"; NSArray *array2 = [NSArray arrayWithContentsOfFile:path]; NSLog(@"array2:%@", array2); } //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); } //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); } //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); } //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); } int main(int argc, const char * argv[]) { @autoreleasepool { arraySort4(); } return 0; }