如何在字符串操作时获取iOS中某些特殊字符之间的数据

Question

我正在尝试从字符串中获取子字符串。这是我的代码：

NSString *haystack = @"1:ketan jogal:1 2:ios developer:2";
NSString*p1=@"1:";
NSString*s1=@":1";
NSString *prefix = @"2:";
NSString *suffix = @":2"; 
NSRange needleRange = NSMakeRange(prefix.length,
                                  haystack.length - prefix.length - suffix.length);
NSRange needlerange1=NSMakeRange(p1.length,
                                  haystack.length - prefix.length - s1.length);

NSString *needle = [haystack substringWithRange:needleRange];
NSString*needle1=[haystack substringWithRange:needlerange1];
NSLog(@"needle1: %@",needle1);
NSLog(@"needle: %@", needle); 

但我每次都失败了，无法获得这样的输出。

2015-01-31 17:07:44.119 WriteintoTextFile[1685:60b] needle1: ketan jogal:1 2:ios developer

你能建议我如何获得这种数据吗？

Answer 1

您可以通过两种方式实现它：

1

使用组件分离dBy字符串方法NSString

NSString *haystack = @"1:ketan jogal:1 2:ios developer:2";
NSArray *arr       = [haystack componentsSeparatedByString:@":"];
NSLog(@"%@",arr[1]);
NSLog(@"%@",arr[3]);

<小时 />

阿拉伯数字

使用 NSScanner

NSScanner *scanner = [[NSScanner alloc] initWithString:haystack];
NSString *result   = nil;
[scanner scanUpToString:@"1:" intoString:nil];
[scanner scanString:@"1:" intoString:nil];
[scanner scanUpToString:@":1" intoString:&result];
NSLog(@"%@",result);
[scanner scanUpToString:@"2:" intoString:nil];
[scanner scanString:@"2:" intoString:nil];
[scanner scanUpToString:@":2" intoString:&result];
NSLog(@"%@",result);