Question

我有一个冗长的字符串，如下所示

请计划参加升级现有代码

早上会见acoomdate bum团队成员

会议号码：457 231 123


加入此会议


转到http://domainname.com

输入密码

现在我想在文字“会议号码”后抓取号码即457 231 123

请帮忙。感谢

修改

让我说我有一个字符串

NSString *myString = @"Please plan to attend to provide upgrade to existing code morning meeting to acoomdate bum team members  Meeting Number: 457 231 123 ----------------------------------------------------- to join this meeting ------------------------------------------------------  1. go to http://domainname.com 2. enter password"

Answer 1

你想要NSScanner。它专门用于此类事情。

NSScanner *scanner = [NSScanner scannerWithString:yourString];
NSString *prefix = @"Meeting number: ";
NSString *numbers;
[scanner scanUpToString:prefix intoString:NULL];
[scanner scanString:prefix intoString:NULL];
[scanner scanUpToCharactersFromSet:[NSCharacterSet newlineCharacterSet] intoString:&numbers];
// numbers now contains the numbers you want.

（这可以通过scanUpToCharactersFromSet:[NSCharacterSet decimalDigitCharacterSet]而不是带有前缀字符串的两行来轻松地找到任何数字。）

Answer 2

您也可以使用正则表达式捕获数字（假设结果中只有数字字符和空格，并且始终有“会议号：”前缀）：

NSString *text = @"Please plan to attend to provide upgrade to existing code\nmorning meeting to acoomdate bum team members\nMeeting Number: 457 231 123\nTo join this meeting\n\ngo to http://domainname.com\nenter password";
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"Meeting Number: ([0-9 ]+)" options:NSRegularExpressionCaseInsensitive error:&error];
NSArray *matches = [regex matchesInString:text
                                  options:0
                                    range:NSMakeRange(0, [text length])];
for (NSTextCheckingResult *match in matches) {
    NSRange matchRange = [match rangeAtIndex:1];
    NSString *result = [text substringWithRange:matchRange]; // Here is the result
}

这可以用来解析多个输入，因为我们在这里有一个循环。如果要求只是解析一个输入，请在声明正则表达式后用以下代码替换代码：

NSTextCheckingResult *match = [regex firstMatchInString:text
                                                options:0
                                                  range:NSMakeRange(0, [text length])];
if (match) {
    NSRange matchRange = [match rangeAtIndex:1];
    NSString *result = [text substringWithRange:matchRange];
}

Answer 3

你可以使用类似的东西 -

NSCharacterSet *nonNumberSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
int numberValue = [[@"Meeting Number: 457 231 123" stringByTrimmingCharactersInSet:nonNumberSet] intValue];

编辑 - 对于所有数字 -

NSCharacterSet *nonNumberSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
int numberValue = [[[@"Meeting Number: 457 231 123" componentsSeparatedByCharactersInSet:nonNumberSet] componentsJoinedByString:@""] intValue];

Answer 4

这样做（一般性很少）：

NSRange promptRange = [bigString rangeOfString:@"Meeting Number: "];
NSRange numberRange = NSMakeRange(promptRange.location + promptRange.length, 11);
NSString *answer = [bigString substringWithRange:numberRange];

Answer 5

就像

一样进入字符串

NSString *str = @"Meeting Number: 457 231 123";

以字符串分隔

NSArray *theList = [str componentsSeparatedByString:@":"];
NSString *getStr = [theList objectAtIndex:1];
[getStr stringByReplacingOccurrencesOfString:@" " withString:@""];

Answer 6

如果你想要一个号码，这应该这样做：

static int ReadMeetingNumber(NSString * string) {
    // ARC:
    // locate the line
    NSString * const prefix = @"Meeting Number: ";
    NSMutableString * meetingNumberLine = nil;
    for (NSString * line in [string componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]]) {
        if ([line hasPrefix:prefix]) {
            meetingNumberLine = [line mutableCopy];
        }
    }

    if (nil == meetingNumberLine) {
        return nil; 
    }
    // trim and get int value
    [meetingNumberLine deleteCharactersInRange:NSMakeRange(0, prefix.length)];
    [meetingNumberLine replaceOccurrencesOfString:@" " withString:@"" options:0 range:NSMakeRange(0, meetingNumberLine.length)];
    return meetingNumberLine.intValue;
}

如果你想找到个人号码，这应该这样做：

// ARC:
// Returns an NSArray of NSNumbers
static NSArray * ReadMeetingNumbers(NSString * string) {
    // locate the line
    NSString * const prefix = @"Meeting Number: ";
    NSMutableString * meetingNumberLine = nil;
    for (NSString * line in [string componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]]) {
        if ([line hasPrefix:prefix]) {
            meetingNumberLine = [line mutableCopy];
        }
    }

    if (nil == meetingNumberLine) {
        return nil; 
    }

    [meetingNumberLine deleteCharactersInRange:NSMakeRange(0, prefix.length)];

    // locate the numbers:
    NSMutableArray * results = [NSMutableArray new];
    for (NSString * at in [meetingNumberLine componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]) {
        const int   intValue = at.intValue;
        if (0 != intValue) {
            [results addObject:[NSNumber numberWithInt:intValue]];
        }
    }
    return [results copy];
}

Answer 7

您可以使用以下代码扫描上述字符串中的所有数字来完成上述任务。

NSString * inputString = @"Please plan to attend to provide upgrade to existing code morning meeting to acoomdate bum team membersMeeting Number: 457 231 123To join this meeting go tohttp://domainname.comenter password"; // Your input string 
NSString * subStr = [inputString substringWithRange:NSMakeRange([inputString rangeOfString:@"Meeting Number:"].location, 27)];
NSString *number = [[subStr componentsSeparatedByCharactersInSet: [[NSCharacterSet decimalDigitCharacterSet] invertedSet]] componentsJoinedByString:@""]; // Scans all numbers from input string
NSLog(@"%@",number); // Your required output printed in console

目标C：如何从字符串中获取子字符串后的数字

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7 个答案: