perl正则小问

落羽飘寻

概括下g{-1}
#=-1时找g{-1}位置上和前一位相同的数
#=-2时找g{-2}位置上和倒数第二位位相同的数
#=-3时找g{-3}位置上和倒数第三位位相同的数

鸡鸡哥

1. #!/usr/bin/perl -w
   
2. use 5.010;
   
3. $_ = "yabba dabba doo";
   
4. if (/abba/) {
   
5. print "1 It matched!\n";
   
6. }else{
   
7. print "1 it is not matched\n";
   
8. }
   
9. $_ = "faceface";
   
10. if (/(face)+/) {
    
11. print "2 It matched!\n";
    
12. }else{
    
13. print "2 it is not matched\n";
    
14. }
    
15. 
    
16. $_ = "yabba dabcba doo";
    
17. if (/y(..).. d\1/) {
    
18. print "3 It matched!\n";
    
19. }else{
    
20. print "3 it is not matched\n";
    
21. }
    
22. 
    
23. $_ = "aa11bb";
    
24. if (/(.)(.)\g{-1}11/) {
    
25. print "4 It matched!\n";
    
26. }else{
    
27. print "4 it is not matched\n";
    
28. }
    
29. 
    
30. 
    
31. 
    
32. 结果是：
    
33. [code]$ ./c1.pl
    
34. 1 It matched!
    
35. 2 It matched!
    
36. 3 It matched!
    
37. 4 it is not matched
    

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[/code]回复 11# 落羽飘寻


    晕了，看了一整，我也是不明白这个g{-1}