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菜鳥學(xué)習(xí):動態(tài)網(wǎng)頁P(yáng)HP基礎(chǔ)學(xué)習(xí)筆記_PHP教程

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推薦:網(wǎng)頁實(shí)例:詳細(xì)介紹用PHP來編寫網(wǎng)頁記數(shù)器
本款計數(shù)器用文本計數(shù)。沒有用到數(shù)據(jù)庫,可以實(shí)現(xiàn)如下功能: 利用一個文本文件實(shí)現(xiàn)多個頁的計數(shù)減少服務(wù)器的I/O占用率在需要紀(jì)錄的文件里,只需加入很少的幾行代碼 基本思路如下: 服務(wù)器

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(對象或類),Array(數(shù)組)

5)特殊數(shù)據(jù)類型:Resourse(對第三方資源(如數(shù)據(jù)庫)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合計賦值操作符: =,*=,/=,-=,%=,.=

5)Automatically Incrementing and Decrementing自動增減操作符:

(1)$variable =1 <=>$variable ;$variable-=1 <=>$variable-,跟c語言一樣,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,&&óand,xor(當(dāng)左右兩邊有且只有一個是true,返回true),!

4、 注釋:

單行注釋:// ,#

多行注釋:/* */

5、 每個語句以;號結(jié)尾,與java相同

6、 定義常量:define(“CONSTANS_NAME”,value)

7、 打印語句:print,與c語言相同

8、 流程控制語句

1)if語句:

(1)if(expression)

{

//code to excute if expression evaluates to true

}

(2)if(expression)

{

}

else

{

}

(3)if(expression1)

{

}

elseif(expression2)

{

}

else

{

}

2)swich語句

switch ( expression )

{

case result1:

// execute this if expression results in result1

break;

case result2:

// 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語句:

(1) while ( expression )
{
// do something
}
(2)do

{

// code to be executed

} while ( expression );

5)for語句:

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)動態(tài)函數(shù)調(diào)用(Dynamic Function Calls):

1: <html>

2: <head>

3: <title>Listing 6.5</title>

4: </head>

5: <body>

6: <?php

7: function sayHello() { //定義函數(shù)sayHello

8: print "hello<br>";

9: }

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

11: $function_holder(); //變量$function_holder成為函數(shù)sayHello的引用,調(diào)用$function_holder()相當(dāng)于調(diào)用sayHello

12: ?>

13: </body>

14: </html>

4)變量作用域:

全局變量:

1: <html>

2: <head>

3: <title>Listing 6.8</title>

4: </head>

5: <body>

6: <?php

7: $life=42;

8: function meaningOfLife() {

9: global $life;

/*在此處重新聲明$life為全局變量,在函數(shù)內(nèi)部訪問全局變量必須這樣,如果在函數(shù)內(nèi)改變變量的值,將在所有代碼片段改變*/

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

11: }

12: meaningOfLife();

13: ?>

14: </body>

15: </html>

5)使用static

1: <html>

2: <head>

3: <title>Listing 6.10</title>

4: </head>

5: <body>

6: <?php

7: 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"); //第一次調(diào)用時,打印$num_of_calls值為1

13: print("We build a fine range of widgets<p>");

14: numberedHeading("Doodads"); /*第一次調(diào)用時,打印$num_of_calls值為2,因為變量是static型的,static型是常駐內(nèi)存的*/

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

16: ?>

17: </body>

18: </html>

6) 傳值(value)和傳址(reference):

傳值:function function_name($argument)

1: <html>

2: <head>

3: <title>Listing 6.13</title>

4: </head>

5: <body>

6: <?php

7: function addFive( $num ) {

8: $num = 5;

9: }

10: $orignum = 10;

11: addFive( &$orignum );

12: print( $orignum );

13: ?>

14: </body>

15: </html>

結(jié)果:10

傳址:funciton function_name(&$argument)

1: <html>

2: <head>

3: <title>Listing 6.14</title>

4: </head>

5: <body>

6: <?php

7: function addFive( &$num ) {

8: $num = 5; /*傳遞過來的是變量$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*/

9: }

10: $orignum = 10;

11: addFive( $orignum );

12: print( $orignum );

13: ?>

14: </body>

15: </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string型參數(shù),第一個是參數(shù)列表,第二個是函數(shù)的主體

1: <html>

2: <head>

3: <title>Listing 6.15</title>

4: </head>

5: <body>

6: <?php

7: $my_anon = create_function( '$a, $b', 'return $a $b;' );

8: print $my_anon( 3, 9 );

9: // prints 12

10: ?>

11: </body>

12: </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)庫與連接建立聯(lián)系:mysql_select_db(database name, connection index);

4) 將SQL語句給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:$newArray = mysql_fetch_array($result);

例子:

1: <?php
2: // open the connection
3: $conn = mysql_connect("localhost", "joeuser", "somepass");
4: // pick the database to use
5: mysql_select_db("testDB",$conn);
6: // create the SQL statement
7: $sql = "SELECT * FROM testTable";
8: // execute the SQL statement
9: $result = mysql_query($sql, $conn) or die(mysql_error());
10: //go through each row in the result set and display data
11: while ($newArray = mysql_fetch_array($result)) {
12: // give a name to the fields
13: $id = $newArray['id'];
14: $testField = $newArray['testField'];
15: //echo the results onscreen
16: echo "The ID is $id and the text is $testField <br>";
17: }
18: ?>

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)向其他頁面:header("Location: http://m.dounai2.com");

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,$str2用來替換的字符串,$str3從這個字符串開始查找替換

3)substr_replace:

14、session:

1)打開session:session_start(); //也可以在php.ini設(shè)置session_auto_start=1,不必再每個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session:$variable =$_SESSION[session_variable_name];

4)銷毀session:session_destroy();

15、顯示分類的完整例子

1: <?php

2: //connect to database

3: $conn = mysql_connect("localhost", "joeuser", "somepass")

4: or die(mysql_error());

5: 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 first

11: $get_cats = "select id, cat_title, cat_desc from

12: store_categories order by cat_title";

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

14:

15: if (mysql_num_rows($get_cats_res) < 1) { //如果返回記錄行數(shù)小于1,則說明沒有分類

16: $display_block = "<P><em>Sorry, no categories to browse.</em></p>";

17: } else {

18:

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

20:$cat_id = $cats[id];

21:$cat_title = strtoupper(stripslashes($cats[cat_title]));

22:$cat_desc = stripslashes($cats[cat_desc]);

23:

24: $display_block .= "<p><strong><a

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

26: <br>$cat_desc</p>";

27:

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

29: //get items

30: $get_items = "select id, item_title, item_price

31: from store_items where cat_id = $cat_id

32: 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>Sorry, no items in

37: this category.</em></p>";

38: } else {

39:

40: $display_block .= "<ul>";

41:

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

43: $item_id = $items[id];

44: $item_title = stripslashes($items[item_title]);

45: $item_price = $items[item_price];

46:

47: $display_block .= "<li><a

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

49: </strong> (\$$item_price)";

[U2] 50: }

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>

16、PHP連接Access

以下為引用的內(nèi)容:
<?
$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();
?>

分享:動態(tài)網(wǎng)頁中直接不讓訪問PHP程序文件
由于我們有需要用到某些php文件,而又不希望別人直接訪問這個文件,我們可以在其他包含文件比如global.php中定義一個參數(shù),在被訪問頁面data.php前面判斷是否定義了該參數(shù),沒有定義則禁止訪問。

來源:模板無憂//所屬分類:PHP教程/更新時間:2008-08-22
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