【Perl读书笔记】数组操作push、pop、shift和unshift

读 《C程序员精通Perl》http://book.douban.com/subject/1232075/   3.2节 笔记

#!/usr/bin/perl

use strict;
use warnings;

my @array = ();

while (1) {
print "input a number or <enter> to finish: ";
my $a=<STDIN>;
chomp ($a);

if ($a eq "") {
last;
}
print "Add $a to array\n";
#@array=(@array, $a);
push(@array, $a);
}

print "\narray=@array\n\n";

my $pop_number = pop(@array);

print "pop_number = $pop_number\n";
print "after pop array=@array\n\n";

my $shift_number = shift @array;
print "shift_number = $shift_number\n";
print "after shift array=@array\n\n";

unshift(@array, 100);
print "after unshift array=@array\n";

运行结果：

[root@localhost perl_practice]# ./read2.pl

input a number or <enter> to finish: 1.^H

Add 1 to array

input a number or <enter> to finish: 2

Add 2 to array

input a number or <enter> to finish: 3

Add 3 to array

input a number or <enter> to finish: 4

Add 4 to array

input a number or <enter> to finish: 5

Add 5 to array

input a number or <enter> to finish: 6

Add 6 to array

input a number or <enter> to finish:

array=1 2 3 4 5 6

pop_number = 6

after pop array=1 2 3 4 5

shift_number = 1.

after shift array=2 3 4 5

after unshift array=100 2 3 4 5

[root@localhost perl_practice]#

数组赋值：

#!/usr/bin/perl

use strict;
use warnings;

my @array = ();

while (1) {
print "input a number or <enter> to finish: ";
my $a=<STDIN>;
chomp ($a);

if ($a eq "") {
last;
}

push(@array, $a);
}

print "array=@array\n";

@array[0, $#array] = (1000, 2000);

print "1 array=@array\n";

@array[0..$#array] = ((9) x ($#array+1));
print "2 array=@array\n";

运行结果：
[root@localhost perl_practice]# ./read3.pl   

input a number or <enter> to finish: 1

input a number or <enter> to finish: 2

input a number or <enter> to finish: 3

input a number or <enter> to finish: 4

input a number or <enter> to finish: 5

input a number or <enter> to finish:

array=1 2 3 4 5

1 array=1000 2 3 4 2000

2 array=9 9 9 9 9

[root@localhost perl_practice]#