PHP 基础知识 (一)

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// 自己最近开始学php ,感觉还是很容易上手的，结合程序来记录这些基础知识以便日后可以看看！！！！

<html>
<body>

<?php
//类
class Calculator{
public function add($x,$y){
return $x+$y;
}
}

$calc = new Calculator;
echo $calc->add(12,412);
echo " "
?>

<?php
//=========字符串和变量 strlen（） strpos（）
$txt = "hello world!";
$num = 16;
$txt1 = "1234";
echo $txt . "\r\n";//空格
echo chr(13).chr(10);

//echo "\n nihao";
echo $num . "\r\n";
echo " "; //换行 是HTML代码，\n是ASCII码，
//浏览器解析的是HTML码，不是ASCII码，
echo $txt . " " . $txt1;
echo "\r\n";
print strlen($txt);

//========php 运算符对值进行运算算数赋值比较逻辑
/*
与java 或者 c 中的运算相似
*/

//=========php if elseif else
$d = date("D");
if($d=="Fri"){
echo "today is Friday ";
echo "See you on Monday!";
}
elseif ($d=="Tue")
echo " today is Tues ,see you latter";
else
echo " See you tommorow";

//switch 语句
$x = 4;
switch ($x){
case 1:
 echo "num 1";
 break;
case 2:
 echo "num 2";
 break;
case 3:
 echo "num 3";
 break;
default :
 echo "other num ";
}
echo " ";
//php 数组
/*数值数组：带有数字ID键的数组其实就是索引
关联数组：数组中的每个ID键关联一个值,类似字典
多维数组：包含一个或多个数组的数组
*/
$names = array("peter","joe","john");
echo $names[0] . " and " . "$names[1]" . " and " . $names[2];

$ages = array("Peter"=>32, "joe"=>30, "john"=>34);
echo " ".$names[0] . " " . $ages['Peter'] . " years old";

$families = array
(
"Griffin"=>array("Peter","Lois","Megan"),
"Quagmire"=>array("Glenn"),
"Brown"=>array("Cleveland","Loretta","Junior")
);

echo " " . $families['Griffin'][0] . " is great!";

//php 循环 while do...while for foreach
$i = 1;
while($i<=5){
echo "The number is " . $i . " ";
$i++;
}

$arr = array("one", "two", "three");
foreach ($arr as $value){
echo "Value: " . $value . " ";
}

//php 函数内置函数
function writeName(){
echo " Peter";
}
writeName();

function writeMy($fname){ //参数
echo " ";
echo $fname . " yang. ";
}
writeMy("john");

function writeMyName($fname,$punctuation)
{
echo $fname . " Yang" . $punctuation . " ";
}

echo "My name is ";
writeMyName("David",".");

function add($valx,$valy){ //有返回值的
$total = $valy + $valx;
return $total;
}
//$ta = add(1,16);
echo "1+16=" . add(1,16);

// php表单和用户输入
//表单验证，应该在任何可能的时候对用户输入进行验证。客户端的验证速度更快，并且可以减轻服务器的负载。

//php 日期 Date()函数 date(format,timestamp) format 可选项 timestamp 时间戳 1970.1.1 以来的秒数
echo " ";
echo date("Y/m/d");
echo " ";
echo date("m d Y"); //只有三个字母对了顺序可以换
echo " ";
echo date("Y-m-d");

//mktime() 函数可为指定的日期返回 Unix 时间戳。
echo " ";
$tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));
echo "明天是 ". date("Y/m/d", $tomorrow); //以明天的时间戳，通过format格式显示

Welcome <?php echo $_GET["name"]; ?>. 
You are <?php echo $_GET["age"]; ?> years old!

Welcome <?php echo $_POST["name"]; ?>. 
You are <?php echo $_POST["age"]; ?> years old.

<h1>
welcome to my home page!
</h1>
 some text

<div class="leftmenu">
<?php include 'menu.php'?>
</div>

<?php
//此函数的第一个参数含有要打开的文件的名称，第二个参数规定了使用哪种模式来打开文件：

echo " ";
$file = fopen("text.txt","r") or exit("unable to open file!");

while (!feof($file)){
echo fgets($file) . " "; //fgets 一行一行的读乱码问题怎么处理
}

fclose($file);

?>

<?php

if ($_FILES["file"]["error"] > 0)
{
echo "Error: " . $_FILES["file"]["error"] . " ";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . " ";
echo "Type: " . $_FILES["file"]["type"] . " ";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb ";
echo "Stored in: " . $_FILES["file"]["tmp_name"];
if (file_exists("upload/" . $_FILES["file"]["name"]))
 {
 echo $_FILES["file"]["name"] . " already exists. ";
 }
 else
 {
 move_uploaded_file($_FILES["file"]["tmp_name"],
 "upload/" . $_FILES["file"]["name"]);
 echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
 }

}
/*
if ((($_FILES["file"]["type"] == "image/gif")
|| ($_FILES["file"]["type"] == "image/jpeg")
|| ($_FILES["file"]["type"] == "image/pjpeg"))
&& ($_FILES["file"]["size"] < 20000))
{
if ($_FILES["file"]["error"] > 0)
 {
 echo "Error: " . $_FILES["file"]["error"] . " ";
 }
else
 {
 echo "Upload: " . $_FILES["file"]["name"] . " ";
 echo "Type: " . $_FILES["file"]["type"] . " ";
 echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb ";
 echo "Stored in: " . $_FILES["file"]["tmp_name"];
 }
}
else
{
echo "Invalid file";
}
*/

</body>
</html>

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