Tinkering with Perl

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Assignment of lists

There are a few ways to assign a list. One way is like this:

@MyFriends = ("John", "Susan", "Mary");

The list is assigned to something described by a left parenthesis ('('), some scalars separated by commas (','), a right parenthesis (')'), and then the semicolon (';'). You can use variables and numbers as well as just strings, like this:

@Numbers = ($LastNumber, 9);

You can also put everything that's in one list, into another list. For example, you might write:

@PeopleIKnow = (@MyFamily, @MyFriends, "Jane", "Bob");

Then the list of people you know includes everybody in the lists of your family and friends, plus Jane and Bob.

One thing you will do often is to add one element to a list. Suppose you have a new friend named Fred, and you want to add him to your list of friends. You could do it this way:

@MyFriends = (@MyFriends, "Fred");

Now, I would like to answer a question you may have == how can MyFriends be equal to itself plus "Fred" added on to the end? That is like saying that a number equals itself plus one.

The answer is that the statement should be read like this: "Let the new value of MyFriends equal the old value of MyFriends, with "Fred" added at the end. It is possible, and useful at times, to use one variable on both sides of the equals sign ('=') in this way.

Tinkering with Perl

Assignment of lists

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