Manipulating the Array Ends

Listing 3.2 shows a program that reads a list of numbers from the user and creates an array out of them.

Listing 3.2. read1.pl
# Note: This program is inefficient 
use strict; 
use warnings; 

my @array = ();    # The list of numbers we have read 

while (1) {  
    print "Input number or <Enter> to finish: "; 
    my $answer = <STDIN>; 
    chomp($answer); 

    if ($answer eq "") {
        last; 
    } 
    @array = (@array, $answer); 
}

The problem is the following line:

@array = (@array, $answer);

This takes the array @array and the scalar $answer and combines them into an array expression. This array expression is then assigned to @array. Because you are computing a new array and doing an entire replacement, this is inefficient.

A more efficient way of doing ...

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