Perl的grep和map有什么作用？

Question

这段代码实际上做了什么？

@array = ('hai','hello','bar','foo') ; 

print grep (/hai/ , @array); 
print grep ("hai",@array) ; 
print map (/hai/ , @array); 
print map ("hai",@array) ; 

Answer 1

试试吧......

print grep (/hai/ , @array); 
hai 
# writes all elements from @array containing 'hai' in them 

print grep ("hai",@array) ; 
haihellobarfoo 
# writes all elements, because "hai" evaluates to true 

print map (/hai/ , @array); 
1 
# writes 1 for the only element from the @array, that contains 'hai' 

print map ("hai",@array) ; 
haihaihaihai 
# maps 'hai' to each element from @array 

Answer 2

它调用map和grep函数。其中的描述可在和map的perlfunc条目中找到。

今天谷歌破碎了吗？