oc学习之NSArray与NSMutableArray数组
- //
- // main.m
- // 6-10复习
- //
- // Created by kj on 14-6-10.
- // Copyright (c) 2014年 kj. All rights reserved.
- //
-
- #import <Foundation/Foundation.h>
-
- int main(int argc, const charchar * argv[])
- {
-
- @autoreleasepool {
- //创建数组对象,NSArray不可变数组
- //c语言的数组可以存放任何类型的数据,同一个数组只能有同一种数据类型
- //oc语言的数组只能存放对象,可以存放任意对象
- // [NSNull null] == 空对象
- //NSArray *arr = [[NSArray alloc] initWithObjects:@"123",@"345",@"abc", nil];
- NSArray *arr1 = @[@"1 2 3", @"345", [NSNull null], @"789"];
- NSArray *arr3 = [[NSArray alloc] initWithArray:arr1];
- NSLog(@"arr = %@",arr3);
-
- //将c数组转换为oc数组对象
- //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
- NSString *carr[10] = {@"123", @"456", @"789"};
- NSArray *arr4 = [[NSArray alloc] initWithObjects:carr count:2];
- NSLog(@"arr4 = %@",arr4);
- //获取元素个数
- NSUInteger count = [arr4 count];
- NSLog(@"count = %ld",count);
- //获取指定下标元素
- NSLog(@"%@",[arr3 objectAtIndex:1]);
- //获取第一个元素或者最后一个元素
- id arrf = [arr3 firstObject];
- id arrl = [arr3 lastObject];
- NSLog(@"%@ %@",arrf,arrl);
- //获取子集
- NSArray *arr2 = @[@"111", @"222", @"333", @"444", @"555", @"666"];
-
- //取出连续范围的元素作为子集内容
- NSArray *sub1 = [arr2 subarrayWithRange:NSMakeRange(1, 3)];
-
- NSLog(@"sub1 = %@", sub1);
- //获取任意元素作为子集
- //1.列出所需要元素的下标清单
- NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];
- //1-1.将要获取元素的下标写入清单
- for (NSInteger i = 0; i < [arr2 count]; i++)
- {
- if (i % 2 != 0)
- {
- [indexs addIndex:i];
- }
- }
-
- //2.将清单交给数组
- //id obj =[arr2 objectAtIndex:0]; //获取单个元素,返回单个元素
- 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)
-
- NSLog(@"sub2 = %@", sub2);
-
- //获取最长字符串和最小字符串
- //快速枚举
- NSArray *arr5 = @[@"123456789", @"222", @"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);
- #if 0
- //创建可变数组对象
- NSMutableArray *arr1 = [[NSMutableArray alloc] initWithCapacity:30];
- NSMutableArray *arr2 = [NSMutableArray arrayWithCapacity:30];
-
- //添加元素
- [arr1 addObject:@"123"];
- [arr1 addObject:@"456"];
-
- [arr2 addObjectsFromArray:arr1];
- [arr2 addObject:@"789"];
- [arr2 addObject:@"789"];
- [arr2 addObject:@"789"];
-
- NSLog(@"arr1 = %@",arr1);
- NSLog(@"arr2 = %@",arr2);
-
- //插入元素
- //插入下标的范围: 0<=index<=count
- [arr1 insertObject:@"aaa" atIndex:1];
- [arr1 insertObject:@"bbb" atIndex:[arr1 count]];
- NSLog(@"arr1 = %@",arr1);
-
- //删除
- [arr2 removeAllObjects];//删除所有元素
- [arr2 removeLastObject];//删除最后一个元素
- [arr2 removeObject:@"789"];//删除指定对象,会将所有对象删除
- [arr2 removeObject:@"789" inRange:NSMakeRange(1, 2)];//删除指定范围中的指定对象
- [arr2 removeObjectAtIndex:0];//删除指定下标的元素
- [arr2 removeObjectsInRange:NSMakeRange(2, 2)];//删除指定范围中得元素
- [arr2 removeObjectIdenticalTo:@"789"];
- [arr2 removeObjectIdenticalTo:@"789" inRange:NSMakeRange(2, 1)];
- //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
- //比如要删下标为偶数的
-
- NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];
-
- for (int i = 0; i < [arr2 count]; i++) {
-
- if (i % 2 == 0) {
-
- [indexs addIndex:i];
- }
-
- }
- //删除清单中得元素
- [arr2 removeObjectsAtIndexes:indexs];
-
-
- //修改数组中得内容
- [arr2 replaceObjectAtIndex:2 withObject:@"aaa"];
- NSArray *arr = @[@"qqqq",@"www",@"ee"];
- [arr2 replaceObjectsAtIndexes:indexs withObjects:arr];
- // qq, 789, ww, 456, ee
- [arr2 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
- [arr2 exchangeObjectAtIndex:1 withObjectAtIndex:3];
- //用oc对c语言中得数组进行排序
- for (int i = 0; i < [arr2 count]; ++i) {
-
- for (int j = i + 1; j < [arr2 count]; ++j) {
-
- if ([arr2[i] length] > [arr2[j] length]) {
-
- [arr2 exchangeObjectAtIndex:i withObjectAtIndex:j];
- }
- }
- }
- NSLog(@"arr2 = %@",arr2);
- #endif
- }
- return 0;
- }
本站仅提供存储服务,所有内容均由用户发布,如发现有害或侵权内容,请
点击举报。