PHP-005-【字符串】-字符串运算

学习要点
字符串表示的整型 浮点型和数字连接在一起时，会发生运算

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<?php
//整型和字符串运算
echo $number = 1 + "10.5"; //11.5 会进行算术运算
echo "<br>";

//
echo $number = 1 + "-1.3e3";//-1299 1+-1300
echo "<br>";
echo '<hr />';

//很奇怪
echo $number = 1 + "bob-1.3e3";//1
echo "<br>";

//很奇怪
echo $number = 1 + "bob3";//1 
echo "<br>";
echo '<hr />';

//下面这种也会发生运算
echo $number = 1 + "10 Small Pigs";//11
echo "<br>";

echo $number = 4 + "10.2 Little Piggies"; //14.2
echo "<br>";

echo $number = "10.0 pigs " + 1;//11
echo "<br>";

echo $number = "10.0 pigs " + 1.0;//11
?>