OC中有已經封裝好的返序方法可以直接調用
NSArray * array = @[@"a", @"b", @"c",@"d"];
//正序
for (NSString * str in array) {
NSLog(@"%@", str);
}
NSLog(@"--------");
//反序
for (NSString * str in [array reverseObjectEnumerator]) {
NSLog(@"%@", str);
}
也可以自定義實現:
//
// ViewController.m
//
//
// Created by hhg on 15-6-15.
// Copyright (c) 2015年 hhg. All rights reserved.
//
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
NSMutableArray *arrM = [[NSMutableArray alloc] initWithArray: @[@"a", @"b", @"c",@"d"]];
NSLog(@"正序 = %@", arrM);
[self reverseArr:arrM];
NSLog(@"反序 = %@", arrM);
}
- (void)reverseArr:(NSMutableArray *)arr {
NSInteger length = arr.count;
for (NSInteger i = 0; i < length / 2; i++) {
[arr exchangeObjectAtIndex:i withObjectAtIndex:length - i - 1];
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}
@end