算术运算符
<?php
$x = 10;
$y = 20;
echo $x + $y;
echo "<br>";
echo $x - $y;
echo "<br>";
echo $x * $y;
echo "<br>";
echo $x / $y;
echo "<br>";
echo $x % $y;
echo "<br>";
// 连接符
echo $x . $y;
echo "<br>";
// 整数之间整除
var_dump(intdiv(10, 3));
赋值运算符
<?php
$x = 10;
$y = 20;
$y = $y += 100;
$z = 50;
$z -= 100;
$i = 5;
$i *= 6;
$j = 10;
$j /= 5;
$k = 15;
$k %= 4;
echo $y;
echo $z;
echo $i;
echo $j;
echo $k;
递增递减运算符
<?php
$x = 10;
echo ++$x; // 11
$y = 10;
echo $y++; // 10
$z = 5;
echo --$z; // 4
$i = 5;
echo $i--; // 5
