如何把一个字符串分解成单个字符

hewangping

UID: 22295
帖子: 96
积分: 220
在线时间: 12 小时

1^# hewangping 发表于 2008-08-27 16:11

如何把一个字符串分解成单个字符

如题

ly5066113

UID: 41125
帖子: 34
积分: 78
在线时间: 1 小时

2^# ly5066113 发表于 2008-08-27 16:29

perl -e '$_ = "abcdefg"; s/(.)/$1\n/g; print'

caining062

UID: 30795
帖子: 25
积分: 57
在线时间: 1 小时

3^# caining062 发表于 2008-08-27 16:56

perl -e '$_ = "how are you 2008";s/ *(\S)/$1\n/g;print'

fengc

UID: 30313
帖子: 67
积分: 154
在线时间: 6 小时

4^# fengc 发表于 2008-08-27 16:57

split //, "abcdef"

forlorngenius

UID: 32353
帖子: 42
积分: 96
在线时间: 2 小时

5^# forlorngenius 发表于 2008-08-27 17:08

unpack

hewangping

UID: 22295
帖子: 96
积分: 220
在线时间: 12 小时

6^# hewangping 发表于 2008-08-27 20:22

多谢楼上诸位。仔细google了一下，转一篇http://www.perlmeme.org/faqs/man ... ing_characters.html的文章总结一下
Solution 1: split

If you pass no seperator into split, it will split on every character:

[Copy to clipboard] [ - ]

CODE:

#!/usr/bin/perl
use strict;
use warnings;

my $string = "Hello, how are you?";

my @chars = split("", $string);

print "First character: $chars[0]\n";

The output of this program is:

First character: H

Solution 2: substr

You can access an individual character using substr:

[Copy to clipboard] [ - ]

CODE:

#!/usr/bin/perl
use strict;
use warnings;

my $string = "Hello, how are you?";
my $char = substr($string, 7, 1);

print "Char is: $char\n";

The above code would output:

Char is: h

Solution 3: Unpack

Like substr, if you want a character from a particular position, you can use unpack:

[Copy to clipboard] [ - ]

CODE:

#!/usr/bin/perl
use strict;
use warnings;

my $string = "Hello, how are you?";
my $char = unpack("x9a1", $string);

print "Char is: $char\n";

The output of this program is:

Char is: w

Solution 4: substr and map

If you want to access all the characters individually, you can build them into an array (like Solution 1) using substr and map:

[Copy to clipboard] [ - ]

CODE:

#!/usr/bin/perl
use strict;
use warnings;

my $string = "Hello, how are you?";
my @chars = map substr( $string, $_, 1), 0 .. length($string) -1;

print "First char is: " . $chars[0] . "\n";

exit 0;

The output of this example would be:

First char is: H

Solution 5: Regular expression

You can use a regular expression to build an array of chars:

[Copy to clipboard] [ - ]

CODE:

#!/usr/bin/perl
use strict;
use warnings;

my $string = "Hello, how are you?";
my @chars = $string =~ /./sg;

print "Fourth char: " . $chars[3] . "\n";

exit 0;

The output of this program is:

Fourth char: l

Solution 6: unpack

unpack can also unpack individual chars into an array:

[Copy to clipboard] [ - ]

CODE:

#!/usr/bin/perl
use strict;
use warnings;

my $string = "Hello, how are you?";
my @chars = unpack 'a' x length $string, $string;

print "Eighth char: $chars[7]\n";

exit 0;

The output would be:

Eighth char: h

See also

perldoc -f split
perldoc -f substr
perldoc -f pack
perldoc -f unpack

forlorngenius

UID: 32353
帖子: 42
积分: 96
在线时间: 2 小时

7^# forlorngenius 发表于 2008-08-27 20:25

google 得力量是强大得

cobrawgl

UID: 21059
帖子: 1
积分: 2
在线时间: 10 分钟

8^# cobrawgl 发表于 2008-08-27 20:25

there is more than one way to do it