OC2_数组操作
// // main.m // OC2_数组操作 // // Created by zhangxueming on 15/6/11. // Copyright (c) 2015年 zhangxueming. All rights reserved. // #import <Foundation/Foundation.h> //NSArray int main(int argc, const char * argv[]) { @autoreleasepool { NSArray *array1 = [[NSArray alloc] initWithObjects:@"one",@"two",@"three",@"four",@"five", nil]; //计算数组的元素的个数 NSInteger cnt = [array1 count]; NSLog(@"cnt = %li", cnt); //获取指定位置的对象 id obj = [array1 objectAtIndex:2]; NSLog(@"obj = %@", obj); //添加数组元素 NSArray *array2 = [array1 arrayByAddingObject:@"six"]; NSLog(@"array2 = %@", array2); //将传入数组中的所有元素添加到数组中 NSArray *otherArray = [[NSArray alloc] initWithObjects:@"hello",@"world", nil]; NSArray *array3 = [array1 arrayByAddingObjectsFromArray:otherArray]; NSLog(@"array3 = %@", array3); //用给定的分割符连接数组中的元素 NSString *str = [array3 componentsJoinedByString:@"##"]; NSLog(@"str = %@", str); //判断是否包含某个对象 BOOL ret = [array3 containsObject:@"hello"]; NSLog(@"ret = %i", ret) ; //返回两个数组中第一个相同的对象 id obj2 = [array3 firstObjectCommonWithArray:otherArray]; NSLog(@"obj2 = %@", obj2); //返回传入对象在数组中第一次出现的位置 NSArray *array4 = [NSArray arrayWithObjects:@"one",@"two",@"three",@"one",@"two", nil]; NSUInteger index = [array4 indexOfObject:@"two"]; NSLog(@"index = %lu", index); //返回传入对象在指定范围内第一次出现的位置 NSUInteger index2 = [array4 indexOfObject:@"two" inRange:NSMakeRange(2, 3)]; NSLog(@"index2 = %lu", index2); //判断两个数组是否相等 BOOL ret3 = [array2 isEqualToArray:array3]; NSLog(@"ret3 = %d", ret3); //获取数组中的第一个元素 id obj3 = [array4 firstObject]; NSLog(@"obj3= %@", obj3); //获取数组中最后一个元素 id obj4 = [array4 lastObject]; NSLog(@"obj4 = %@", obj4); //数组的遍历 //方法一: 下标法 NSArray *array5 = @[@"one",@"two",@"three",@"four"]; NSUInteger len = [array5 count]; for (NSInteger i=0; i<len; i++) { NSLog(@"%@", [array5 objectAtIndex:i]); } //方法二: 枚举器法 //生成枚举器对象 NSEnumerator *enumerator = [array5 objectEnumerator]; id item = nil; while (item = [enumerator nextObject]) { NSLog(@"item = %@", item); } //倒序遍历数组 NSEnumerator *reverseEnumerator = [array5 reverseObjectEnumerator]; id item2 = nil; while (item2 = [reverseEnumerator nextObject]) { NSLog(@"item = %@", item2); } //方法三: 快速枚举法 for (id item in array5) { NSLog(@"%@", item); } //数组排序 NSArray *array6 = @[@"one",@"two",@"three",@"four",@"five"]; NSArray *sortArray = [array6 sortedArrayUsingSelector:@selector(compare:)]; NSLog(@"sortArray = %@", sortArray); //数组提取 NSArray *subArray = [array6 subarrayWithRange:NSMakeRange(1, 3)]; NSLog(@"subArray = %@", subArray); //以给定下标集合提取数组 NSMutableIndexSet *indexSet = [[NSMutableIndexSet alloc] initWithIndex:0]; [indexSet addIndex:2]; [indexSet addIndex:4]; NSArray *subArray2 = [array6 objectsAtIndexes:indexSet]; NSLog(@"subArray2 = %@", subArray2); } return 0; }