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               當(dāng)前位置:首頁(yè)>軟件介紹>PHP入門學(xué)習(xí)基礎(chǔ)教程 查詢:
               
          PHP入門學(xué)習(xí)基礎(chǔ)教程

                  1、 PHP片段四種表示形式。

                  標(biāo)準(zhǔn)tags:<?php ?>

                  short tags:<? ?> 需要在php.ini中設(shè)置short _open_tag=on,默認(rèn)是on asp tags: <% %>需要在php.ini中設(shè)置asp_tags=on,默認(rèn)是off script tags:<script language=”php”></script>

                  2、 PHP變量及數(shù)據(jù)類型

                  1) $variable ,變量以字母、_開(kāi)始,不能有空格

                  2) 賦值$variable=value;

                  3) 弱類型,直接賦值,不需要顯示聲明數(shù)據(jù)類型

                  4) 基本數(shù)據(jù)類型:Integer,Double,String,Boolean,Object(對(duì)象或類),Array(數(shù)組)

                  5) 特殊數(shù)據(jù)類型:Resourse(對(duì)第三方資源(如數(shù)據(jù)庫(kù))的引用),Null(空,未初始化的變量)

                  3、 操作符

                  1) 賦值操作符:=

                  2) 算術(shù)操作符:+,-,*,/,%(取模)

                  3) 連接操作符:. ,無(wú)論操作數(shù)是什么,都當(dāng)成String,結(jié)果返回String 4) Combined Assignment Operators合計(jì)賦值操作符:+=,*=,/=,-=,%=,.= 5) Automatically Incrementing and Decrementing自動(dòng)增減操作符: (1)$variable+=1 <=>$variable++;$variable-=1 <=>$variable-,跟c語(yǔ)言一樣,先做其他操作,后++或-

                  (2)++$variable,-$variable,先++或-,再做其他操作

                  6) 比較操作符:= =(左邊等于右邊),~=(左邊不等于右邊),= = =(左邊等于右邊,且數(shù)據(jù)類型相同),>=,>,<,<=

                  7) 邏輯操作符:|| ó or,&&óa(chǎn)nd,xor(當(dāng)左右兩邊有且只有一個(gè)是true,返回true),!

                  4、 注釋:

                  單行注釋:// ,#

                  多行注釋:/* */

                  5、 每個(gè)語(yǔ)句以;號(hào)結(jié)尾,與java相同

                  6、 定義常量:define(“CONSTANS_NAME”,value)

                  7、 打印語(yǔ)句:print,與c語(yǔ)言相同

                  8、 流程控制語(yǔ)句

                  1) if語(yǔ)句:

                  (1)if(expression)

                  {

                  //code to excute if expression evaluates to true

                  }

                  (2)if(expression)

                  {

                  }

                  else

                  {

                  }

                  (3)if(expression1)

                  {

                  }

                  elseif(expression2)

                  {

                  }

                  else

                  {

                  }

                  2) swich語(yǔ)句

                  switch ( expression )

                  {

                  case result

                  // execute this if expression results in result1

                  break;

                  case result

                  // execute this if expression results in result2

                  break;

                  default:

                  // execute this if no break statement

                  // has been encountered hitherto }

                  3) ,操作符:

                  ( expression )?returned_if_expression_is_true:returned_if_expression_is_false;

                  4) while語(yǔ)句:

                  (1) while ( expression ) {

                  // do something }

                  (2)do

                  {

                  // code to be executed

                  } while ( expression ); 5) for語(yǔ)句:

                  for ( initialization expression; test expression; modification expression ) {

                  // code to be executed

                  }

                  6) break;continue

                  9、 編寫函數(shù)

                  1) 定義函數(shù):

                  function function_name($argument1,$argument2,??) //形參 {

                  //function code here;

                  }

                  2) 函數(shù)調(diào)用

                  function_name($argument1,$argument2,??); //形參 3) 動(dòng)態(tài)函數(shù)調(diào)用(Dynamic Function Calls): <h<head>

                  <title>Listing 6.5</title> </head>

                  <body>

                  <?php

                  function sayHello() { //定義函數(shù)sayHello print "hello<br>";

                  }

                  $function_holder = "sayHello"; //將函數(shù)名賦值給變量$function_holder

                  $function_holder(); //變量$function_holder成為函數(shù)sayHello的引用,調(diào)用

                  $function_holder()相當(dāng)于調(diào)用sayHello ?>

                  </body>

                  </html>

                  4) 變量作用域:

                  全局變量:

                  <html>

                  <head>

                  <title>Listing 6.8</title> </head>

                  <body>

                  <?php

                  $life=42;

                  function meaningOfLife() { global $life;

                  /*在此處重新聲明$life為全局變量,在函數(shù)內(nèi)部訪問(wèn)全局變量必須這樣,如果在函數(shù)內(nèi)改

                  變變量的值,將在所有代碼片段改變*/

                  print "The meaning of life is $life<br>";

                  }

                  meaningOfLife();

                  ?>

                  </body>

                  </html>

                  5) 使用static

                  <html>

                  <head>

                  <title>Listing 6.10</title> </head>

                  <body>

                  <?php

                  function numberedHeading( $txt ) {

                  static $num_of_calls = 0;

                  $num_of_calls++;

                  print "<h1>$num_of_calls. $txt</h1>"; }

                  numberedHeading("Widgets"); //第一次調(diào)用時(shí),打印$num_of_calls值為1 print("We build a fine range of widgets<p>");

                  numberedHeading("Doodads"); /*第一次調(diào)用時(shí),打印$num_of_calls值為2,因?yàn)樽兞渴?/p>

                  static型的,static型是常駐內(nèi)存的*/

                  print("Finest in the world<p>"); ?>

                  </body>

                  </html>

                  6) 傳值(value)和傳址(reference):

                  傳值:function function_name($argument) <html>

                  <head>

                  <title>Listing 6.13</title> </head>

                  <body>

                  <?php

                  function addFive( $num ) { $num += 5;

                  }

                  $orignum = 10;

                  addFive( &$orignum );

                  print( $orignum );

                  ?>

                  </body>

                  </html>

                  結(jié)果:10

                  傳址:funciton function_name(&$argument) <html>

                  <head>

                  <title>Listing 6.14</title> </head>

                  <body>

                  <?php

                  function addFive( &$num ) { $num += 5; /*傳遞過(guò)來(lái)的是變量$num的引用,因此改變形參$num的值就是真正改變變量

                  $orignum物理內(nèi)存中保存的值*/

                  }

                  $orignum = 10;

                  addFive( $orignum );

                  print( $orignum );

                  ?>

                  </body>

                  </html>

                  結(jié)果:15

                  7) 創(chuàng)建匿名函數(shù):create_function(‘string1’,’string2’); create_function是PHP內(nèi)建函數(shù),專門用于創(chuàng)建匿名函數(shù),接受兩個(gè)string型參數(shù),第一個(gè)是參數(shù)列表,第

                  二個(gè)是函數(shù)的主體

                  <html>

                  <head>

                  <title>Listing 6.15</title>

                  </head>

                  <body>

                  <?php

                  $my_anon = create_function( '$a, $b', 'return $a+$b;' ); print $my_anon( 3, 9 );

                  // prints 12

                  ?>

                  </body>

                  </html>

                  8) 判斷函數(shù)是否存在:function_exists(function_name),參數(shù)為函數(shù)名

                  10、 用PHP連接MySQL

                  1) 連接:&conn=mysql_connect("localhost", "joeuser", "somepass"); 2) 關(guān)閉連接:mysql_close($conn);

                  3) 數(shù)據(jù)庫(kù)與連接建立聯(lián)系:mysql_select_db(database name, connection index); 4) 將SQL語(yǔ)句給MySQL執(zhí)行:$result = mysql_query($sql, $conn); //增刪改查都是這

                  句

                  5) 檢索數(shù)據(jù):返回記錄數(shù):$number_of_rows = mysql_num_rows($result); 將記錄放入數(shù)組:$newArray = mysql_fe 例子:

                  <?php

                  // open the connection

                  $conn = mysql_connect("localhost", "joeuser", "somepass");

                  // pick the database to use

                  mysql_select_db("testDB",$conn);

                  // create the SQL statement

                  $sql = "SELECT * FROM testTable";

                  // execute the SQL statement

                  $result = mysql_query($sql, $conn) or die(mysql_error());

                  //go through each row in the result set and display data

                  while ($newArray = mysql_fetch_array($result)) {

                  // give a name to the fields

                  $id = $newArray['id'];

                  $testField = $newArray['testField'];

                  //echo the results onscreen

                  echo "The ID is $id and the text is $testField <br>";

                  }

                  ?>

                  11、 接受表單元素:$_POST[表單元素名],

                  如<input type=text name=user>ó$_POST[user]

                  接受url中queryString中值(GET方式):$_GET[queryString]

                  12、轉(zhuǎn)向其他頁(yè)面:header("Location: "); 13、字符串操作:

                  1)explode(“-”,str)óJava中的splite

                  2)str_replace($str1,$str2,$str3) =>$str1要查找的字符串,$str2用來(lái)替換的字符串,

                  $str3從這個(gè)字符串開(kāi)始查找替換

                  3)substr_replace:

                  14、session:

                  1)打開(kāi)session:session_start(); //也可以在php.ini設(shè)置session_auto_start=1,不

                  必再每個(gè)script都寫這句,但是默認(rèn)為0,則必須要寫。

                  2)給session賦值:$_SESSION[session_variable_name]=$variable; 3)訪問(wèn)session:$variable =$_SESSION[session_variable_name]; 4)銷毀session:session_destroy();

                  15、顯示分類的完整例子:

                  <?php

                  //connect to database

                  $conn = mysql_connect("localhost", "joeuser", "somepass") or die(mysql_error());

                  mysql_select_db("testDB",$conn) or die(mysql_error()); $display_block = "<h1>My Categories</h1> <P>Select a category to see its items.</p>"; //show categories first

                  $get_cats = "select id, cat_title, cat_desc from store_categories order by cat_title";

                  $get_cats_res = mysql_query($get_cats) or die(mysql_error());

                  if (mysql_num_rows($get_cats_res) < 1) { //如果返回記錄行數(shù)小于1,則說(shuō)明沒(méi)有分類 $display_block = "<P><em>Sorry, no categories to browse.</em></p>";

                  } else {

                  while ($cats = mysql_fetch_array($get_cats_res)) { //將記錄放入變量$cats中

                  $cat_id = $cats[id];

                  $cat_title = strtoupper(stripslashes($cats[cat_title])); $cat_desc = stripslashes($cats[cat_desc]); $display_block .= "<p><strong><a

                  href="$_SERVER[PHP_SELF][U1] ?cat_id=$cat_id">$cat_title</a></strong>//點(diǎn)擊此url,刷新本頁(yè),第28行讀取cat_id,顯示相應(yīng)分類的條目

                  <br>$cat_desc</p>";

                  if ($_GET[cat_id] == $cat_id) { //選擇一個(gè)分類,看下面的條目

                  //get items

                  $get_items = "select id, item_title, item_price from store_items where cat_id = $cat_id

                  order by item_title";

                  $get_items_res = mysql_query($get_items) or die(mysql_error());

                  if (mysql_num_rows($get_items_res) < 1) { $display_block = "<P><em>Sorry, no items in this category.</em></p>";

                  } els$display_block .= "<ul>";

                  while ($items = mysql_fetch_array($get_items_res)) {

                  $item_id = $items[id];

                  $item_title = stripslashes($items[item_title]); $item_price = $items[item_price]; $display_block .= "<li><a

                  href="showitem.php?item_id=$item_id">$item_title</a>

                  </strong> ($$item_price)";

                  [U2] }

                  $display_block .= "</ul>";

                  }

                  }

                  }

                  }

                  ?>

                  <HTML>

                  <HEAD>

                  <TITLE>My Categories</TITLE>

                  </HEAD>

                  <BODY>

                  <? print $display_block; ?>

                  </BODY>

                  </HTML>

                  16、PHP連接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->fields["UserName"];

                  $fld0=$rs->fields["Password"];

                  ....

                  echo "$fld0->value $fld1->value ...."; $rs->movenext();

                  }

                  $rs->close();

                  ?>

                   

                  


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