📅 最后修改于: 2021-01-07 08:28:15 🧑 作者: Mango
字符串是Perl语言的重要组成部分。它们是标量变量，因此它们以($)符号开头。可以在单引号(')或双引号(“)中定义字符串。
运算符可以轻松地以不同方式操作字符串。字符串运算符有两种类型：
Perl字符串用(。)符号而不是(+)符号连接。
$firstName = "Christian";
$lastName = "Grey";
$fullName = $firstName . " " . $lastName;
print "$fullName\n";
输出：
Christian Grey
Perl字符串可以使用(x)变量重复多次。
$text = "Thank You ";
$output = $text x 3;
print "$output\n";
输出：
Thank You Thank You Thank You
在Perl中，要声明一个字符串在变量名之前使用my关键字。
可以使用以下语法初始化和声明字符串：
my $variableName = "";
在此示例中，我们显示了如何初始化和声明字符串。我们通过以下方式一起打印了几个字符串：
我们已经展示了所有三种print输出的方法。
use strict;
use warnings;
# Declaring and initializing a string.
my $msg1 = "Welcome at JavaTpoint.";
my $msg2 = "This is our Perl Tutorial.";
#printing using . operator.
print $msg1 . "" . $msg2. "\n";
#print as separate arguments.
print $msg1, "",$msg2, "\n";
#embedd string in a bigger string.
print "$msg1$msg2\n";
输出：
Welcome at JavaTpoint. This is our Perl Tutorial.
Welcome at JavaTpoint. This is our Perl Tutorial.
Welcome at JavaTpoint. This is our Perl Tutorial.
| Character | Description |
|---|---|
| \a | Bell |
| \b | Gives a backspace |
| \cX | Control the characters. X is a character. |
| \e | escape next character |
| \E | it ends \u, \l and \q function |
| \f | Gives formfedd to the string |
| \l | Transformation of only next letter into lower case. |
| \L | Transformation of all letters into lower case. |
| \n | Begins next line from a new line |
| \0nn | Octal format numbers are created |
| \Q | Do not match the pattern |
| \r | Gives a carriage return |
| \t | Gives a tab to the string |
| \u | Transformation of only next letter into lower case. |
| \U | Transformation of letters into uppercase. |
| \xnn | Hexadecimal format numbers are created |
字符串可以放在单引号(')或双引号(“)中，但它们的行为几乎没有什么不同。
my $user = 'Ana';
print 'Hello $user, welcome at our site.\n';
print "\n";
my $user = 'Ana';
my $day = "today";
print "Hello $user, welcome at our site $day.\n";
输出：
Hello $user, welcome at our site.\n
Hello Ana, welcome at our site today.
单引号中的所有字符均按原样解释。
双引号提供插值。表示字符串存在的其他变量将代表它们的值。转义字符将被其值替换，例如'\ n'将显示换行符。
substr()函数用于截断字符串。我们需要提供一个偏移量字符串。字符串将被截断直到提供的偏移值。
提及偏移量的长度将在偏移值之后print字符串，直到提到的长度为止。
如果提供具有偏移量和长度的新字符串，它将替换偏移量后的字符串，直到长度值为止。
use strict;
use warnings;
# Original string
my $originalstring = "Our site javaTpoint provides all type of tutorials";
print "$originalstring\n";
# Offset of 4
my $offset = substr($originalstring, 4);
print "$offset\n";
# Offset of 4, length 15
my $offsetlength = substr($originalstring, 4, 15);
print "$offsetlength\n";
# Replacing length with the new string
my $replacing = substr($originalstring, 4, 15, "one and only site");
print "$originalstring\n";
输出：
Our site javaTpoint provides all type of tutorials
site "javaTpoint" provides all type of tutorials
site javaTpoint
Our one and only site provides all type of tutorials
Perl字符串始终与eq而不是(==)进行比较。它检查两个字符串是否相等。
my $string1 = "Ana";
my $string2 = "Ana";
if($string1 eq $string2) {
print "Match!\n";
}
my $string3 = "Ana";
my $string4 = "Christian";
if($string3 eq $string4) {
print "Match\n!";
}else{
print "Missmatch!\n";
}
输出：
Match!
Missmatch!
Perl字符串的长度可以使用length()函数确定。
my $msg = "Our site javaTpoint provides all type of tutorials";
print "String Length : ", length($msg), "\n";
输出：
String Length : 50
一个字符串可以用两种方式替换为另一个字符串。
在第一个中，我们用Lions替换了Tigers ，它在字符串用s ///出现。
在第二篇中，我们用s /// g全局替换了花朵的玫瑰。
my $var1 = "Tigers are big and frightening.";
$var1 =~ s/Tigers/Lions/;
print "$var1\n";
my $var2 = "Red roses are very popular. Yellow roses are less seen.";
$var2 =~ s/roses/flowers/g;
print "$var2\n";
输出：
Lions are big and frightening.
Red flowers are very popular. Yellow flowers are less seen.
Perl提供了一个match运算符(=〜)从字符串找到一个子字符串。
my $var = "Tigers are big and frightening.";
if($var =~ /frightening/)
{
print "Matched\n";
}else{
print "Match not Found\n";
}
if($var =~ /biggest/)
{
print "Matched\n";
}else{
print "Match not Found\n";
}
输出：
Matched
Match not Found
可以使用(。=)运算符将两个字符串连接在一起。
my $str1 = "Where there is a will,";
my $str2 = "there is a way.\n";
my $joining = '';
$joining = $str1 . ' ';
$joining .= $str2;
print $joining;
输出：
Where there is a will, there is a way.