| Escape Sequence | Description |
| \a | Bell (beep) |
| \b | Backspace |
| \cn | The Ctrl+n character |
| \e | Escape |
| \E | Ends the effect of \L, \U or \Q |
| \f | Form feed |
| \l | Forces the next letter into lowercase |
| \L | All following letters are lowercase |
| \n | Newline |
| \r | Carriage return |
| \Q | Do not look for special pattern characters |
| \t | Tab |
| \u | Force next letter into uppercase |
| \U | All following letters are uppercase |
| \v | Vertical tab |
\L、\U、\Q功能可以由\E關(guān)閉掉，如：
$a = "T\LHIS IS A \ESTRING"; # same as "This is a STRING"
.要在字符串中包含雙引號(hào)或反斜線，則在其前加一個(gè)反斜線，反斜線還可以取消變量替換，如：
$res = "A quote \" and A backslash \\";
$result = 14;
print ("The value of \$result is $result.\n")的結(jié)果為：
The value of $result is 14.
.可用\nnn(8進(jìn)制)或\xnn(16進(jìn)制)來(lái)表示ASCII字符，如：
$result = "\377"; # this is the character 255,or EOF
$result = "\xff"; # this is also 255
.單引號(hào)字符串
單引號(hào)字符串與雙引號(hào)字符串有兩個(gè)區(qū)別，一是沒(méi)有變量替換功能，二是反斜線不支持轉(zhuǎn)義字符，而只在包含單引號(hào)和反斜線時(shí)起作用。單引號(hào)另一個(gè)特性是可以跨多行，如：
$text = 'This is two
lines of text
';
與下句等效：
$text = "This is two\nlines of text\n";
.字符串和數(shù)值的互相轉(zhuǎn)換
例1：
$string = "43";
$number = 28;
$result = $string + $number; # $result = 71
若字符串中含有非數(shù)字的字符，則從左起至第一個(gè)非數(shù)字的字符，如：
$result = "hello" * 5; # $result = 0
$result = "12a34" +1; # $result = 13
.變量初始值
在PERL中，所有的簡(jiǎn)單變量都有缺省初始值：""，即空字符。但是建議給所有變量賦初值，否則當(dāng)程序變得大而復(fù)雜后，很容易出現(xiàn)不可預(yù)料且很難調(diào)試的錯(cuò)誤。
標(biāo)簽：六安 自貢 松原 石嘴山 鄂州 河北 宜春 淄博
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