如何按其中包含的数字对 NSStrings 数组进行排序？（按升序排列）答案

【问题标题】：How to sort an array of NSStrings by the number contained within? (in ascending order)如何按其中包含的数字对 NSStrings 数组进行排序？（按升序排列）
【发布时间】：2011-10-27 16:53:07
【问题描述】：

我想知道是否可以根据其中包含的数字值对 NSStrings 的 NSArray 进行排序。基本上它是进程 ID 和进程名称的列表，我想根据进程 ID 对进程进行排序。数组如下所示：

"286             Google Chrome He",
"1209             ibtool",
"0             kernel_task",
"1             launchd",
"10             kextd",
"11             notifyd",
"12             diskarbitrationd",
"13             configd",
"14             syslogd",
"15             DirectoryService",
"16             distnoted",
"18             ntpd",
"22             SystemStarter",
"25             securityd",
"28             mds",
"29             mDNSResponder",
"30             loginwindow",
"31             KernelEventAgent",
"33             hidd",
"34             fseventsd",
"36             dynamic_pager",
"42             blued",
"43             autofsd",
"46             WDSmartWareD",
"47             WDDMService",
"61             coreservicesd",
"62             WindowServer",
"71             HWPortCfg",
"72             HWNetCfg",
"159             socketfilterfw",
"165             cvmsServ",
"177             coreaudiod",
"191             vmnet-bridge",
"196             vmnet-dhcpd",
"198             vmnet-netifup",
"200             vmnet-dhcpd",
"204             vmnet-natd",
"206             vmnet-netifup",
"220             launchd",
"224             Dock",
"225             SystemUIServer",
"226             Finder",
"228             pboard",
"229             fontd",
"240             UserEventAgent",
"247             AirPort Base Sta",
"252             iprint-listener",
"253             StatusMenu",
"254             Dropbox",
"271             dbfseventsd",
"275             Google Chrome",
"295             Google Chrome He",
"298             AppleSpell",
"634             Google Chrome He",
"696             Google Chrome He",
"730             Microsoft Word",
"733             Microsoft Databa",
"736             Microsoft AU Dae",
"1095             usbmuxd",
"1110             Xcode",
"1171             Interface Builde",
"1282             Interface Builde",
"1283             Interface Builde",
"1475             Google Chrome He",
"1531             Google Chrome He",
"1533             Google Chrome He",
"1681             Google Chrome He",
"1682             Google Chrome He",
"1686             Google Chrome He",
"1687             Google Chrome He",
"1692             Google Chrome He",
"1945             Google Chrome He",
"2088             Keynote",
"2268             Google Chrome He",
"2326             Google Chrome He",
"2481             Google Chrome He",
"2545             Google Chrome He",
"2596             Google Chrome He",
"2766             mdworker",
"2933             Google Chrome He",
"2963             iPhone Simulator",
"2967             SimulatorBridge",
"2970             lsd",
"2971             SpringBoard",
"2982             ocspd",
"2998             installd",
"3000             TableViewControl",
"3001             taskgated",
"3002             gdb-i386-apple-d"

非常感谢任何帮助！

【问题讨论】：

你到底为什么不把这些字符串转换成更有用的东西？？
因为我只需要在 UITableView 中显示它们。 :)

标签： iphone objective-c nsstring nsarray

【解决方案1】：

是的，你可以使用下面的 NSArray 实例方法：

- (NSArray *)sortedArrayUsingFunction:(NSInteger (*)(id, id, void *))comparator context:(void *)context

您需要定义一个带有三个参数的 int 函数：要比较的两个数组元素和一个上下文。它返回一个 NSComparisonResult（-1、0 或 1）。例如：

NSInteger firstWordIntCompare(id stringLeft, id stringRight, void *context)
{
    // Extract number from stringLeft and stringRight
    NSArray *wordsLeft = [stringLeft componentsSeparatedByString:@" "];
    NSArray *wordsRight = [stringRight componentsSeparatedByString:@" "];
    NSString *firstWordLeft = wordsLeft.count ? [wordsLeft objectAtIndex:0] : nil;
    NSString *firstWordRight = wordsRight.count ? [wordsRight objectAtIndex:0] : nil;
    int intLeft = [firstWordLeft intValue];
    int intRight = [firstWordRight intValue];

    if (intLeft < intRight)
        return NSOrderedAscending;
    else if (intLeft > intRight)
        return NSOrderedDescending;
    else 
        return NSOrderedSame;
}

然后通过使用您的函数调用 NSArray 方法返回排序后的数组：

NSArray *sortedArray = [origArray sortedArrayUsingFunction:firstWordIntCompare context:NULL];

【讨论】：

【解决方案2】：

对于您的情况，最简单的方法是使用排序描述符：

NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"integerValue" ascending:YES];
NSArray *sortedArray = [originalArray sortedArrayUsingDescriptors:[NSArray arrayWithObject:sort]];

【讨论】：