1.PHP基础知识
<?php
echo "hello";
?>
2.变量
<?php
error_reporting(E_ALL);
name="张三"；//age=20;
echo $name;
echo ‘
’;
//echo age;echogettype(name);
name=80;echo′<br>′;echoname;
echo’
’;
echo gettype($name);
3.常量
<?php
//echo _FILE_;
//echo PHP_VERSION;
$yn = ture;
//if(!defined('PI')){
//define('PI',3.14);
//}
const PI = 3.14;
$r=5;
$s=PI * $r *$r //计算面积
echo $s;
4运算
<?php
header('content-type:text/html;charset=utf-8');
//练习求余
// $m=5;
// $n=2;
//echo $m%$n;
//2018是否闰年，标准：能被4整除但（并且）不能被100整除，或可以被400整除的年份
$year = 2018;
// if(){
//}
if(($year %4 == 0 && $year % 100 !=0) || ($year % 400 ==0)){
echo'2018是闰年';
}else{
echo'2018是平年'；
}