perl-basic-数组操作

RT。。。直接看代码

my @stack = ("Fred", "Eileen", "Denise", "Charlie");
# remove at tail
pop @stack;
print @stack;

# add to tail
push @stack, "Bob", "Alice";
print @stack;

# remove at head
shift @stack;
print @stack;

# add to head
unshift @stack, "Hank", "Grace";
print @stack;

# 其实pop,push,shift,unshift是特殊的splice
my @stack = ("Fred", "Eileen", "Denise", "Charlie");
# splice 返回分割结果，这里是得到EileenDenise
print splice(@stack, 1, 2, "<<<", ">>>");
print "
";
# 将分割结果替换为<<<和>>>
print @stack;
print "
";

• 实用函数
• join and reverse

my @elements = ("Antimony", "Arsenic", "Aluminum", "Selenium");
print @elements;             # "AntimonyArsenicAluminumSelenium"
# 有了空格：）
print "@elements";           # "Antimony Arsenic Aluminum Selenium"
# 使用,连接
print join(", ", @elements); # "Antimony, Arsenic, Aluminum, Selenium"

# list，所以按元素逆序
print reverse("Hello", "World");        # "WorldHello"
# 前面加了scalar，所以即使是list，也先组合在一起，然后按字母逆序
print scalar reverse("Hello", "World"); # "dlroWolleH"

• map and grep

my @capitals = ("Baton Rouge", "Indianapolis", "Columbus", "Montgomery", "Helena", "Denver", "Boise");
# 对@capitals中的元素使用uc函数
# http://perldoc.perl.org/functions/map.html
print join ", ", map { uc $_ } @capitals;
# "BATON ROUGE, INDIANAPOLIS, COLUMBUS, MONTGOMERY, HELENA, DENVER, BOISE"