运算符

-- Start

Perl 除了支持其他语言都支持的运算符外，它还支持一些特殊的运算符。

算术运算符

#!/usr/bin/perl$x = 2;$y = 3;$r = $x + $y; #加print "$r\n";$r = $x - $y; #减print "$r\n";$r = $x * $y; #乘print "$r\n";$r = $x / $y; #除print "$r\n";$r = $x ** $y; #幂，相当于2的3次方print "$r\n";$r = $x % $y; #余print "$r\n";

 

数字比较运算符

#!/usr/bin/perl$x = 2;$y = 3;if($x < $y) {print "$x < $y\n";}if($x > $y) {print "$x > $y\n";}if($x == $y) {print "$x == $y\n";}if($x <= $y) {print "$x <= $y\n";}if($x >= $y) {print "$x >= $y\n";}if($x != $y) {print "$x > $y\n";}$r = ($x <=> $y);if($r == -1) {print "$x < $y\n";}elsif ($r == 0) {print "$x == $y\n";}elsif ($r == 1) {print "$x > $y\n";}

 

串比较运算符

#!/usr/bin/perl$x = 'a';$y = 'b';if($x lt $y) {print "$x less than $y\n";}if($x gt $y) {print "$x greater than $y\n";}if($x eq $y) {print "$x equals $y\n";}if($x le $y) {print "$x less equal $y\n";}if($x ge $y) {print "$x greater equal $y\n";}if($x ne $y) {print "$x not equal $y\n";}$r = ($x cmp $y);if($r == -1) {print "$x less than $y\n";}elsif ($r == 0) {print "$x equals $y\n";}elsif ($r == 1) {print "$x greater than $y\n";}

 

串连接和串重复

#!/usr/bin/perl$x = 'a';$y = 'b';# 字符串连接$r = $x.$y; # 结果为 abprint "$r\n";# 字符串重复$r = 'a' x 3; # 结果为 aaa

 

逻辑运算符

#!/usr/bin/perl$x = 'a';$y = 'b';$z = 'c';if($x > $y && $y > $z) {print "test &&\n";}if($x > $y || $y > $z) {print "test ||\n";}if(!($x > $y)) {print "test !\n";}if($x > $y and $y > $z) {print "test and\n";}if($x > $y or $y > $z) {print "test or\n";}if(not($x > $y)) {print "test not\n";}if($x > $y xor $y > $z) {print "test xor\n";}

 

位运算符

#!/usr/bin/perl# 按位与 &# 按位或 |# 按位非 ~# 按位异或 ^# 左移(相当于乘2) <<# 右移(相当于除2) >>

赋值运算符

#!/usr/bin/perl# =# +=# -=# *=# /=# %=# **=# &=# |=# ^=# .=

自增自减运算符

#!/usr/bin/perl# ++# --

逗号运算符

#!/usr/bin/perl$a+=1,$b=$a;$a+=1;$b=$a;

条件运算符

#!/usr/bin/perl$x = 2;$y = 3;$r = ($x > $y) ? ($x - $y) : ($y - $x);print $r;

 

-- 更多参见：Perl 精萃

-- 声 明：转载请注明出处
-- Last Updated on 2012-06-19
-- Written by ShangBo on 2012-06-18
-- End