Perl function

split, join

$words = "the cat is white";

($w1, $w2, $w3, $w4) = split(/ /,$words);

结果是： the cat is white;

split可以写成这个样： （@words) = split(/ /, $words);

Join

$joined = join(" ", ("A", "black", "dog"));

print "$joined\n";

结果： A black dog #有

lc, uc, lcfirst, ucfirst

$words = "nz";

$words = lc($words);

all lower case,都要小写；

lcfirst第一个字母小写

$words = "ADADSFS";

$words = lcfirst($words);

print $words; 结果是aDADSFS;

length, substr, index, rindex

length("thursday"); 结果是8；

$string = "It was hot on thursday.";

substr($string, 14, 6);

从第14个字母开始（从0数），6个字母

结果是thursd;

substr($string, 14, 8, "tuesday");

结果是It was hot on tuesday.

$string = "There, here & everywhere";

$index = index($string, "here");

print "First 'here', position $index\n";

结果是： First 'here', position 1

rindex是last position;

$string = "There, here & everywhere";