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1、PHP基础学习笔记1、PHP片段四种表示形式。标准tags：<?php?>short tags：<?> 需要在php.ini中设置short _open_tag=on，默认是onasp tags： <%>需要在php.ini中设置asp_tags=on，默认是offscript tags：<script language=”php”></script>2、PHP变量及数据类型1)$variable，变量以字母、_开始，不能有空格2)赋值$variable=value;3)弱类型，直接赋值，不需要显示声明数据类型4)基本数据类型：Integer，Doubl
2、e,String,Boolean,Object,Array(数组)5)特殊数据类型：Resourse的引用），Null3、操作符1)赋值操作符：=2)算术操作符：+，-，*，/，%3)连接操作符：. ，无论操作数是什么，都当成String，结果返回String4)Combined Assignment Operators合计赋值操作符：+=，*=，/=，-=，%=，.=5)Automatically Incrementing and Decrementing自动增减操作符：$variable+=1 <=>$variable+；$variable-=1 <=>$variable-
3、,跟c语言一样，先做其他操作，后+或-+$variable，-$variable，先+或-，再做其他操作6)比较操作符：= =，！=，= = =，>=，>，<，<=7)逻辑操作符：| or，&and，xor(当左右两边有且只有一个是true，返回true)，!4、注释：单行注释：/ ，#多行注释：/*/5、每个语句以;号结尾，与java相同6、定义常量：define(“CONSTANS_NAME”,value)7、打印语句：print,与c语言相同8、流程控制语句1)if语句：if(expression)/code to excute if expression evaluat
4、es to trueif(expression) else(3)if(expression1)elseif(expression2)else2)swich语句switch ( expression )case result1:/ execute this if expression results in result1break;case result2:/ execute this if expression results in result2break;default:/ execute this if no break statement/ has been encountered h
5、itherto3)？操作符：( expression )?returned_if_expression_is_true:returned_if_expression_is_false;4)while语句： while ( expression )/ do somethingdo/ code to be executed while ( expression );5)for语句：for ( initialization expression; test expression; modification expression ) / code to be executed6)break；conti
6、nue9、编写函数1)定义函数：function function_name($argument1,$argument2,) /形参 /function code here;2)函数调用function_name($argument1,$argument2,); /形参3)动态函数调用：1: <html>2: <head>3: <title>Listing 6.5</title>4: </head>5: <body>6: <?php7: function sayHello /定义函数sayHello8: print hello<br>
7、;9: 10: $function_holder = sayHello;/将函数名赋值给变量$function_holder11: $function_holder;/变量$function_holder成为函数sayHello的引用，调用$function_holder相当于调用sayHello12: ?>13: </body>14: </html>4)变量作用域：全局变量：1: <html>2: <head>3: <title>Listing 6.8</title>4: </head>5: <body>6: <?php
8、7: $life=42;8: function meaningOfLife 9:global $life;/*在此处重新声明$life为全局变量，在函数内部访问全局变量必须这样，如果在函数内改变变量的值，将在所有代码片段改变*/10:print The meaning of life is $life<br>11: 12: meaningOfLife;13: ?>14: </body>15: </html>5)使用static1: <html>2: <head>3: <title>Listing 6.10</title>4: <
9、/head>5: <body>6: <?php7: function numberedHeading( $txt ) 8:static $num_of_calls = 0;9:$num_of_calls+;10:print <h1>$num_of_calls. $txt</h1>11: 12: numberedHeading(Widgets);/第一次调用时，打印$num_of_calls值为113: print(We build a fine range of widgets<p>);14: numberedHeading(Doodads);/*第一
10、次调用时，打印$num_of_calls值为2，因为变量是static型的，static型是常驻内存的*/15: print(Finest in the world<p>);16: ?>17: </body>18: </html>6)传值和传址：传值：function function_name($argument)1: <html>2: <head>3: <title>Listing 6.13</title>4: </head>5: <body>6: <?php7: function addFive( $num
11、) 8:$num += 5;9: 10: $orignum = 10;11: addFive( &$orignum );12: print( $orignum );13: ?>14: </body>15: </html>结果：10传址：funciton function_name(&$argument)1: <html>2: <head>3: <title>Listing 6.14</title>4: </head>5: <body>6: <?php7: function addFive( &$num ) 8:$num +
12、= 5;/*传递过来的是变量$num的引用，因此改变形参$num的值就是真正改变变量$orignum物理内存中保存的值*/9: 10: $orignum = 10;11: addFive( $orignum );12: print( $orignum );13: ?>14: </body>15: </html>结果：157)创建匿名函数：create_function(string1,string2); create_function是PHP内建函数，专门用于创建匿名函数，接受两个string型参数，第一个是参数列表，第二个是函数的主体1: <html>2: <
13、head>3: <title>Listing 6.15</title>4: </head>5: <body>6: <?php7: $my_anon = create_function( $a, $b, return $a+$b; );8: print $my_anon( 3, 9 );9: / prints 1210: ?>11: </body>12: </html>8)判断函数是否存在：function_exists(function_name),参数为函数名10、用PHP连接MySQL1)连接：&conn=mysql_connec
14、t(localhost, joeuser, somepass);2)关闭连接：mysql_close($conn);3） 数据库与连接建立联系：mysql_select_db(database name, connection index);4） 将SQL语句给MySQL执行：$result = mysql_query($sql, $conn); /增删改查都是这句5） 检索数据：返回记录数：$number_of_rows = mysql_num_rows($result);将记录放入数组：$newArray = mysql_fetch_array($result);例子：1: <?php
15、2: / open the connection3: $conn = mysql_connect(localhost, joeuser, somepass);4: / pick the database to use5: mysql_select_db(testDB,$conn);6: / create the SQL statement7: $sql = SELECT * FROM testTable;8: / execute the SQL statement9: $result = mysql_query($sql, $conn) or die(mysql_error);10: /go
16、through each row in the result set and display data11: while ($newArray = mysql_fetch_array($result) 12: / give a name to the fields13: $id = $newArrayid;14: $testField = $newArraytestField;15: /echo the results onscreen16: echo The ID is $id and the text is $testField <br>17: 18: ?>11、接受表单元素
17、：$_POST表单元素名，如<input type=textname=user>$_POSTuser接受url中queryString中值：$_GETqueryString12、转向其他页面：header(Location: );13、字符串操作：1）explode(“-”,str)Java中的splite2）str_replace =>$str1要查找的字符串，$str2用来替换的字符串，$str3从这个字符串开始查找替换3）substr_replace：14、session：1）打开session：session_start; /也可以在php.ini设置session_aut
18、o_start=1，不必再每个script都写这句，但是默认为0，则必须要写。2）给session赋值：$_SESSIONsession_variable_name=$variable;3)访问session：$variable =$_SESSIONsession_variable_name;4）销毁session：session_destroy;15、显示分类的完整例子：1: <?php2: /connect to database3: $conn = mysql_connect(localhost, joeuser, somepass)4: or die(mysql_error);5:
19、 mysql_select_db(testDB,$conn) or die(mysql_error);6:7: $display_block = <h1>My Categories</h1>8: <P>Select a category to see its items.</p>9:10: /show categories first11: $get_cats = select id, cat_title, cat_desc from12: store_categories order by cat_title;13: $get_cats_res = mysq
20、l_query($get_cats) or die(mysql_error);14:15: if (mysql_num_rows($get_cats_res) < 1) /如果返回记录行数小于1，则说明没有分类16:$display_block = <P><em>Sorry, no categories to browse.</em></p>17: else 18:19:while ($cats = mysql_fetch_array($get_cats_res) /将记录放入变量$cats中20:$cat_id = $catsid;21:$cat_tit
21、le = strtoupper(stripslashes($catscat_title);22:$cat_desc = stripslashes($catscat_desc);23:24:$display_block .= <p><strong><a25:href=$_SERVERPHP_SELFU1 ?cat_id=$cat_id>$cat_title</a></strong>/点击此url，刷新本页，第28行读取cat_id，显示相应分类的条目26:<br>$cat_desc</p>27:28:if ($_GETcat_id = $
22、cat_id) /选择一个分类，看下面的条目29:/get items30:$get_items = select id, item_title, item_price31:from store_items where cat_id = $cat_id32:order by item_title;33:$get_items_res = mysql_query($get_items) or die(mysql_error);34:35:if (mysql_num_rows($get_items_res) < 1) 36:$display_block = <P><em>Sorr
23、y, no items in37:this category.</em></p>38: else 39:40:$display_block .= <ul>41:42:while ($items = mysql_fetch_array($get_items_res) 43:$item_id = $itemsid;44:$item_title = stripslashes($itemsitem_title);45:$item_price = $itemsitem_price;46:47:$display_block .= <li><a48:href=show
24、item.php?item_id=$item_id>$item_title</a>49:</strong> ($item_price);U250:51:52:$display_block .= </ul>53:54:55: 56: 57: ?>58: <HTML>59: <HEAD>60: <TITLE>My Categories</TITLE>61: </HEAD>62: <BODY>63: <? print $display_block; ?>64: </BODY>65: </HTML&g
25、t16、PHP连接Access：<?$dbc=new com(adodb.connection);$dbc->open(driver=microsoft access driver (*.mdb);dbq=c:member.mdb);$rs=$dbc->execute(select * from tablename);$i=0;while (!$rs->eof)$i+=1$fld0=$rs->fieldsUserName;$fld0=$rs->fieldsPassword;.echo $fld0->value $fld1->value .;$rs->movenext;$rs->close;?>
