有关数组

zlzty

我想问个问题，比如我有一个数组@a=（aa,bb,cc,dd,ee,ff,ad,fe,ag,hh,ssd,ffg,h,j,k,l,asdfag)可能有上百个，现在我这么操作
for($i=0;$i<=$#a;$i++)
{
   if($a[$i]=~/ee/)
  {
     $a = $i;
  }
  elsif($a[$i]=~/j/)
{
   $b = $i;
}  
}
大致是这样。我想要的是提取dd到k之间的所有元素放到新的数组中（包括dd和k）并且将他们在元数组中删除。。我应该怎么做啊？
我最初的想发是push（@number，$a[$a-1..$b+1]);不过好像这样操作是无效的。。
谁会的话请指教下。谢谢

yinyuemi

回复 1# zlzty

1. perl -le '
   
2. @a=(aa,bb,cc,dd,ee,ff,ad,fe,ag,hh,ssd,ffg,h,j,k,l,asdfag);
   
3. map{$i++;if(/dd/../k/){push @b,$_;splice(@a,--$i,1)}}@a;
   
4. print "@b","\n","@a"'
   
5. dd ee ff ad fe ag hh ssd ffg h j k
   
6. aa bb cc l asdfag
   

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iLRainyday

1. #!/usr/bin/perl
   
2. 
   
3. use strict;
   
4. use warnings;
   
5. 
   
6. my @arr = qw(aa bb cc dd ee ff ad fe ag hh ssd ffg h j k l asdfag);
   
7. my @filtered = grep { /^dd$/../^k$/ } @arr;
   
8. 
   
9. my %final;
   
10. @final{@arr} = ();
    
11. delete @final{@filtered};
    
12. my @output = keys %final;
    
13. print "@output";

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zlzty

3Q回复 3# iLRainyday


   

zlzty

3Q回复 2# yinyuemi


   

只是一个红薯

yinyuemi 发表于 2012-12-12 00:56
回复 1# zlzty

请问下怎么把握$i的变化，我重写成foreach的形式就不对了

zlzty

请问splice（@a，--$i，1）这里的1是做什么用的。我记得splice（@a，--$i）这个应该是$i是多少，就删除@a中第几个元素是吗？那1是做什么用的。。我删了1，好像1到最后的元素就都没了回复 2# yinyuemi


   

只是一个红薯

就是一次取出1个元素回复 7# zlzty


   

只是一个红薯

yinyuemi 发表于 2012-12-12 00:56
回复 1# zlzty

1. for(@a){
   
2.        $i++;
   
3.     if(/dd/../k/){
   
4.         
   
5.           #say "$i";
   
6.         splice(@a,--$i,1);
   
7.            push @b,$_;
   
8.         say "@a","\n","@b";
   
9.     }
   
10. }

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哪里不对了。。

yinyuemi

回复 6# 只是一个红薯


    [code]The foreach loop iterates over a normal list value and sets the variable VAR to be each element of the list in turn. If the variable is preceded with the keyword my, then it is lexically scoped, and is therefore visible only within the loop. Otherwise, the variable is implicitly local to the loop and regains its former value upon exiting the loop. If the variable was previously declared with my, it uses that variable instead of the global one, but it's still localized to the loop. This implicit localization occurs only in a foreach loop.

The foreach keyword is actually a synonym for the for keyword, so you can use either. If VAR is omitted, $_ is set to each value.

If any element of LIST is an lvalue, you can modify it by modifying VAR inside the loop. Conversely, if any element of LIST is NOT an lvalue, any attempt to modify that element will fail. In other words, the foreach loop index variable is an implicit alias for each item in the list that you're looping over.

If any part of LIST is an array, foreach will get very confused if you add or remove elements within the loop body, for example with splice. So don't do that.

foreach probably won't do what you expect if VAR is a tied or other special variable. Don't do that either.[/code]