Hello fellow monks, I have the following question. This example is kind of contrived; I am doing this to test out an algorithm for a larger project. I have the following in an array: 
apple chocolate ice-cream
apple chocolate pie
apple chocolate custard
apple caramel ice-cream
apple caramel pie
apple caramel custard
apple vanilla ice-cream
apple vanilla pie
apple vanilla custard
banana chocolate ice-cream
banana chocolate pie
banana chocolate custard
banana caramel ice-cream
banana caramel pie
banana caramel custard
banana vanilla ice-cream
banana vanilla pie
banana vanilla custard
orange chocolate ice-cream
orange chocolate pie
orange chocolate custard
orange caramel ice-cream
orange caramel pie
orange caramel custard
orange vanilla ice-cream
orange vanilla pie
orange vanilla custard

[download]
I have another array with the following: 
apple chocolate pie
apple caramel custard
banana caramel ice-cream
orange vanilla pie

[download]
What I'm trying to do is remove all items present in the second array, from the first array. To do that, I have this line of code:

map {@yum = grep {!/$_/} @yum;} @bad;

@yum is the first array and @bad is the second. The problem is that when I run this code, @yum is empty. However, when the equivalent statements produced by the map are run, I get the desired result. 
@yum = grep {!/apple chocolate pie/} @yum;
@yum = grep {!/apple caramel custard/} @yum;
@yum = grep {!/banana caramel ice-cream/} @yum;
@yum = grep {!/orange vanilla pie/} @yum;

[download]
Why is this happening?

In reply to Map not working as expected. by vivin

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