如何解析Objective C中的字符串

Question

有人可以帮我从Objective C中的字符串"/ Date(1242597600000)/"中提取int时间戳值

我想得到1242597600000.

谢谢

Answer 1

一个简单的方法:

NSString *timestampString = @"\/Date(1242597600000)\/";
NSArray *components = [timestampString componentsSeparatedByString:@"("];
NSString *afterOpenBracket = [components objectAtIndex:1];
components = [afterOpenBracket componentsSeparatedByString:@")"];
NSString *numberString = [components objectAtIndex:0];
long timeStamp = [numberString longValue];

或者,如果您知道字符串将始终具有相同的长度和格式,您可以使用:

NSString *numberString = [timestampString substringWithRange:NSMakeRange(7,13)];

另一种方法:

NSRange openBracket = [timestampString rangeOfString:@"("];
NSRange closeBracket = [timestampString rangeOfString:@")"];
NSRange numberRange = NSMakeRange(openBracket.location + 1, closeBracket.location - openBracket.location - 1);
NSString *numberString = [timestampString substringWithRange:numberRange];

Answer 2

有不止一种方法可以做到这一点.这是一个使用NSScanner的建议;

NSString *dateString = @"\/Date(1242597600000)\/";
NSScanner *dateScanner = [NSScanner scannerWithString:dateString];
NSInteger timestamp;

if (!([dateScanner scanInteger:&timestamp])) {
    // scanInteger returns NO if the extraction is unsuccessful
    NSLog(@"Unable to extract string");
}

// If no error, then timestamp now contains the extracted numbers.