Perl 赋值运算符示例
假设变量 $a 持有 10,变量 $b 持有 20,那么下面是 Perl 中可用的赋值运算符及其用法 −
序号 | 运算符 & 描述 |
---|---|
1 | = 简单赋值运算符,将右侧操作数的值分配给左侧操作数 示例 − $c = $a + $b 将 $a + $b 的值赋给 $c |
2 | += 加 AND 赋值运算符,它将右操作数添加到左操作数并将结果分配给左操作数 示例 − $c += $a 等价于 $c = $c + $a |
3 | -= 减 AND 赋值运算符,它从左操作数中减去右操作数并将结果分配给左操作数 示例 − $c -= $a 等价于 $c = $c - $a |
4 | *= 乘 AND 赋值运算符,它将右操作数与左操作数相乘并将结果分配给左操作数 示例 − $c *= $a 等价于 $c = $c * $a |
5 | /= 除法 AND 赋值运算符,它将左操作数与右操作数相除并将结果分配给左操作数 示例 − $c /= $a 等价于 $c = $c / $a |
6 | %= 模 AND 赋值运算符,它使用两个操作数取模并将结果分配给左操作数 示例 − $c %= $a 等价于 $c = $c % a |
7 | **= 指数与赋值运算符,对运算符执行指数(幂)计算并将值赋给左操作数 示例 − $c **= $a 等价于 $c = $c ** $a |
示例
试试下面的例子来理解 Perl 中所有可用的赋值运算符。 将以下 Perl 程序复制并粘贴到 test.pl 文件中并执行该程序。
#!/usr/local/bin/perl $a = 10; $b = 20; print "Value of \$a = $a and value of \$b = $b\n"; $c = $a + $b; print "After assignment value of \$c = $c\n"; $c += $a; print "Value of \$c = $c after statement \$c += \$a\n"; $c -= $a; print "Value of \$c = $c after statement \$c -= \$a\n"; $c *= $a; print "Value of \$c = $c after statement \$c *= \$a\n"; $c /= $a; print "Value of \$c = $c after statement \$c /= \$a\n"; $c %= $a; print "Value of \$c = $c after statement \$c %= \$a\n"; $c = 2; $a = 4; print "Value of \$a = $a and value of \$c = $c\n"; $c **= $a; print "Value of \$c = $c after statement \$c **= \$a\n";
当上面的代码被执行时,它会产生下面的结果 −
Value of $a = 10 and value of $b = 20 After assignment value of $c = 30 Value of $c = 40 after statement $c += $a Value of $c = 30 after statement $c -= $a Value of $c = 300 after statement $c *= $a Value of $c = 30 after statement $c /= $a Value of $c = 0 after statement $c %= $a Value of $a = 4 and value of $c = 2 Value of $c = 16 after statement $c **= $a