qinglongquan

php继承总结： 1、父类中public protectde的属性和方法被继承，private 的属性和方法不被继承 2、子类只能继承一个父类，但是可以多层继承 3、默认父类的构造方法不会被执行

<?php header("content-type:image/jpeg"); $width = 100; $heith =40; $element = array("q","w","e","r","t","y","u","i","o","p","a","s","d","f","g","h","j","k","l","z","x","c","v","b","n","m","1","2","3",

ceil()函数采取进一法取整，只要小数点后的值不为0，都会进一，从而取得比原数大的最小整数，但类型还是float。floor()函数采取舍去法取整，不管小数点后是什么都舍去，从而取得一个比原数小的最大整数，但类型还是float。round()函数采取的则是四舍五入法则，具体数值由保留的小数位和相应位的数字大小决定。intval()函数则是单纯地取得浮点数的整数部分，类型为integer。