From 55859460de2454f298661e209cd4df32ca397f16 Mon Sep 17 00:00:00 2001 From: Kevin Kee Date: Sat, 7 Jun 2003 17:27:52 +0000 Subject: [PATCH] new file git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@130571 c90b9560-bf6c-de11-be94-00142212c4b1 --- language/variables.xml | 415 +++++++++-------------------------------- 1 file changed, 89 insertions(+), 326 deletions(-) diff --git a/language/variables.xml b/language/variables.xml index fb3452a56f..ab762ecd6e 100644 --- a/language/variables.xml +++ b/language/variables.xml @@ -1,28 +1,22 @@ - - + + - Variables + 各類變數 - Basics + 基本知識 - Variables in PHP are represented by a dollar sign followed by the - name of the variable. The variable name is case-sensitive. + 所有 PHP 的變數都是以 "$" 為開端，後加變數名所組成的。變數名稱是有大小寫之分的。 - Variable names follow the same rules as other labels in PHP. A - valid variable name starts with a letter or underscore, followed - by any number of letters, numbers, or underscores. As a regular - expression, it would be expressed thus: - '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*' + PHP 的變數名稱和其他標籤有著相同的規則。一個有效的變數是由英文字母或底線開始，跟著是任意長短的字母、數字或底線。按正規運算式，它可以表達為：'[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*' - For our purposes here, a letter is a-z, A-Z, and the ASCII - characters from 127 through 255 (0x7f-0xff). + 字母為 a-z，A-Z，而 ASCII 字符則從 127 至 255〈0x7f-0xff〉。 @@ -45,33 +39,14 @@ $t - In PHP 3, variables are always assigned by value. That is to say, - when you assign an expression to a variable, the entire value of - the original expression is copied into the destination - variable. This means, for instance, that after assigning one - variable's value to another, changing one of those variables will - have no effect on the other. For more information on this kind of - assignment, see the chapter on Expressions. + PHP 3 中，變數總是由值指派。也就是說，當您將一個運算式的值指派給一個變數時，整個原始運算式的值將會複製到目的變數。例如，當將一個變數的值指派給另一個變數之後，更改當中的任何一個變數的值並不會影響到另一個變數的值。想要知道更多這類的指派，請參閱運算式這一章。 - PHP 4 offers another way to assign values to variables: - assign by reference. - This means that the new variable simply references (in other words, - "becomes an alias for" or "points to") the original variable. - Changes to the new variable affect the original, and vice versa. - This also means that no copying is performed; thus, the assignment - happens more quickly. However, any speedup will likely be noticed - only in tight loops or when assigning large - arrays or - objects. + PHP 4 則提供了另一種指派變數值的方法：傳址指派，即新變數只是參照原來變數中的值，或說新的變數成為原來變數的別名。此時，更改兩個變數中任何一個的值都會同時更改另一個的值。由於沒有執行實際的複製工作，指派的操作也因此更加快捷。不過，只有在緊密的迴圈或指派大量的陣列或物件時才會察覺速度的提升。 - To assign by reference, simply prepend an ampersand (&) to the - beginning of the variable which is being assigned (the source - variable). For instance, the following code snippet outputs 'My - name is Bob' twice: - + 使用傳址指派，只須在被參照的原變數前加上一個 (&) 的符號。例如，下列程式碼在使用傳址指派後輸出 'My name is Bob' 兩次。 + - One important thing to note is that only named variables may be - assigned by reference. + 需要注意的是只有真正命名的變數才可以用來進行傳址指派。 - Predefined variables + 預設的變數 - PHP provides a large number of predefined variables to any script - which it runs. Many of these variables, however, cannot be fully - documented as they are dependent upon which server is running, the - version and setup of the server, and other factors. Some of these - variables will not be available when PHP is run on the - command line. - For a listing of these variables, please see the section on - Reserved Predefined Variables. + PHP 為它執行的程式提供了大量的預設變數。然而，由于有許多變數因依賴其所執行的伺服器種類、版本、安裝等情況而定，因此難以有完整的被記載下來。更有一些變數在指令行的模式運行時是不能使用的。有關這些變數的列表，請參考保留的先前定義變數一節。 - In PHP 4.2.0 and later, the default value for the PHP directive register_globals is - off. This is a major change in PHP. Having - register_globals off affects the set of predefined - variables available in the global scope. For example, to get - DOCUMENT_ROOT you'll use - $_SERVER['DOCUMENT_ROOT'] instead of - $DOCUMENT_ROOT, or $_GET['id'] from - the URL http://www.example.com/test.php?id=3 instead - of $id, or $_ENV['HOME'] instead of - $HOME. + PHP 4.2.0 以後的版本，register_globals 指令的預設值是 off。這是一個重大的改變。將 register_globals 的值預設為 off 會影響到預設變數在全域範圍內的有效性。例如，要得到 DOCUMENT_ROOT 的值，應使用 $_SERVER['DOCUMENT_ROOT'] 而不是 $DOCUMENT_ROOT、使用 $_GET['id'] 以取得 URL http://www.example.com/test.php?id=3 中 id 的值，而不是用 $id、或使用 $_ENV['HOME'] 來取代 $HOME。 - For related information on this change, read the configuration entry for - register_globals, the security - chapter on Using Register Globals - , as well as the PHP 4.1.0 - and 4.2.0 Release - Announcements. + 更多與此更改相關的資料可在 register_globals 的設置一節、使用 Register Globals 中的安全章，或在 4.1.0 及 4.2.0 的發行通告中取得。 - Using the available PHP Reserved Predefined Variables, like the - superglobal arrays, - is preferred. + 我們建議您使用 PHP 提供的保留預設變數，如 superglobal 陳列。 - From version 4.1.0 onward, PHP provides an additional set of predefined arrays - containing variables from the web server (if applicable), the - environment, and user input. These new arrays are rather special - in that they are automatically global--i.e., automatically - available in every scope. For this reason, they are often known as - 'autoglobals' or 'superglobals'. (There is no mechanism in PHP for - user-defined superglobals.) The superglobals are listed below; - however, for a listing of their contents and further discussion on - PHP predefined variables and their natures, please see the section - Reserved Predefined Variables. - Also, you'll notice how the older predefined variables - ($HTTP_*_VARS) still exist. - + 自 4.1.0 版本起，PHP 額外提供了一套預設陣列，當中包含了來自伺服器〈如適用〉、環境、及使用者輸入的變數。這些新陳列比較特別，因此它們會自動地設為全域，即可以在所有範圍內使用。正因如此，它們也被稱為 'autoglobals' 或 'superglobals'。〈PHP 尚未有使用者自行定義 superglobals 的功能。〉我們將在下面列出 superglobals，但要知道它們的內容和 PHP 預設變數的深入討論，請參考保留的先前定義變數一節。此外，您也會留意舊有的預設變數 ($HTTP_*_VARS) 仍然存在。 + &avail.register-long-arrays; - Variable variables + 可變變數 - Superglobals cannot be used as - variable variables. + Superglobals 不能當作可變變數來使用。 - If certain variables in variables_order are not set, their - appropriate PHP predefined arrays are also left empty. + 如果某些 variables_order 中的變數沒有被設定，它們相對的 PHP 預設陳列也將會是空的。 - PHP Superglobals + PHP 的 Superglobals $GLOBALS - Contains a reference to every variable which is currently - available within the global scope of the script. The keys of - this array are the names of the global variables. - $GLOBALS has existed since PHP 3. + 包含一個指向程式全域範圍內可用變數的索引。此陳列的索引鍵為全域變數的名稱。$GLOBALS 自 PHP 3 開始就已存在。 @@ -202,10 +135,7 @@ $bar = &test(); // Invalid. $_SERVER - Variables set by the web server or otherwise directly related - to the execution environment of the current script. Analogous - to the old $HTTP_SERVER_VARS array (which is - still available, but deprecated). + 由網頁伺服器設定的變數或目前的程式所執行的環境產生的變數。其性質類似舊有的 $HTTP_SERVER_VARS 陳列，雖然目前還可以使用，但不被建議。 @@ -213,9 +143,7 @@ $bar = &test(); // Invalid. $_GET - Variables provided to the script via HTTP GET. Analogous to the - old $HTTP_GET_VARS array (which is still - available, but deprecated). + 通過 HTTP GET 提供給程式的變數。其性質類似舊有的 $HTTP_GET_VARS 陳列，雖然目前還可以使用，但不被建議。 @@ -223,9 +151,7 @@ $bar = &test(); // Invalid. $_POST - Variables provided to the script via HTTP POST. Analogous to the - old $HTTP_POST_VARS array (which is still - available, but deprecated). + 通過 HTTP POST 提供給程式的變數。其性質類似舊有的 $HTTP_POST_VARS陳列，雖然目前還可以使用，但不被建議。 @@ -233,9 +159,7 @@ $bar = &test(); // Invalid. $_COOKIE - Variables provided to the script via HTTP cookies. Analogous to - the old $HTTP_COOKIE_VARS array (which is - still available, but deprecated). + 通過 HTTP cookies 提供給程式的變數。其性質類似舊有的 $HTTP_COOKIE_VARS陳列，雖然目前還可以使用，但不被建議。 @@ -243,12 +167,7 @@ $bar = &test(); // Invalid. $_FILES - Variables provided to the script via HTTP post file - uploads. Analogous to the old - $HTTP_POST_FILES array (which is still - available, but deprecated). See POST method - uploads for more information. + 通過 HTTP POST 檔案上傳提供給程式的變數。其性質類似舊有的 $HTTP_POST_FILES陳列，雖然目前還可以使用，但不被建議。詳情請參閱 POST 上傳方式。 @@ -256,9 +175,7 @@ $bar = &test(); // Invalid. $_ENV - Variables provided to the script via the environment. Analogous - to the old $HTTP_ENV_VARS array (which is - still available, but deprecated). + 執行環境提供給程式的變數。其性質類似舊有的 $HTTP_ENV_VARS陳列，雖然目前還可以使用，但不被建議。 @@ -266,20 +183,11 @@ $bar = &test(); // Invalid. $_REQUEST - Variables provided to the script via any user input mechanism, - and which therefore cannot be trusted. The presence and order - of variable inclusion in this array is defined according to the variables_order - configuration directive. This array has no direct analogue in - versions of PHP prior to 4.1.0. See also - import_request_variables. + 通過任何使用者輸入途徑而提供給程式的變數，也正因如此不值得信任。此陳列中變數的存在與否及次序是決定於 variables_order 的設定。PHP 4.1.0 之前的版本並沒有類似此陳列的變數。請同時參閱 import_request_variables。 - When running on the command line - , this will not include the - argv and argc entries; these are - present in the $_SERVER array. + 在指令行模式下執行時，它並不包含 argv 和 argc 項目。此兩項目只在 $_SERVER 陳列中出現。 @@ -288,12 +196,7 @@ $bar = &test(); // Invalid. $_SESSION - Variables which are currently registered to a script's - session. Analogous to the old - $HTTP_SESSION_VARS array (which is still - available, but deprecated). See the Session handling functions section - for more information. + 目前和程式注冊了的 session 變數。其性質類似舊有的 $HTTP_SESSION_VARS陳列，雖然目前還可以使用，但不被建議。詳情請參閱 Session 處理函數一節。 @@ -303,13 +206,10 @@ $bar = &test(); // Invalid. - Variable scope + 變數範圍 - The scope of a variable is the context within which it is defined. - For the most part all PHP variables only have a single scope. - This single scope spans included and required files as well. For - example: + 變數的範圍只是在其所定義的空間內存在。在大部份的情況下，PHP 的變數只有一個單一的範圍。這單一的範圍也包含了以 include 和 require 方式引入的檔案。例如： @@ -322,11 +222,7 @@ include "b.inc"; - Here the $a variable will be available within - the included b.inc script. However, within - user-defined functions a local function scope is introduced. Any - variable used inside a function is by default limited to the local - function scope. For example: + 例子中，變數 $a 也存在于被包含入的程式 b.inc 中。但是在使用者自訂的函數中，一個區域性的函數範圍將被引用。任何在函數內使用的變數在預設的情況下只局限於該函數的範圍內。例如： @@ -347,16 +243,7 @@ Test(); - This script will not produce any output because the echo statement - refers to a local version of the $a variable, - and it has not been assigned a value within this scope. You may - notice that this is a little bit different from the C language in - that global variables in C are automatically available to - functions unless specifically overridden by a local definition. - This can cause some problems in that people may inadvertently - change a global variable. In PHP global variables must be - declared global inside a function if they are going to be used in - that function. An example: + 這個程式不會輸出任何東西，因為 echo 述句使用了本區域版本的 $a 變數，而該本區域變數並未曾被分配一個值。你會發現這和 C 語言的做法不同，因為 C 的全域變數是自動的提供給各函數，除非在本域定義中指明撤銷。此做法可能會引致一些問題，如使用者不慎地更改了全域變數的值。在 PHP 中，全域變數在本域使用前必須先宣佈為全域。例子： @@ -381,17 +268,11 @@ echo $b; - The above script will output "3". By declaring - $a and $b global within the - function, all references to either variable will refer to the - global version. There is no limit to the number of global - variables that can be manipulated by a function. + 上述例子將會輸出 "3"。在函數內宣佈 $a 及 $b 為全域後，所有涉及該兩個變數的使用將自動指向全域的版本。PHP 沒有限定一個函數可以使用的全域變數的數量。 - A second way to access variables from the global scope is to use - the special PHP-defined $GLOBALS array. The - previous example can be rewritten as: + 第二種存取全域範圍中的變數方法是使用一個由 PHP 特別定義的陳列：$GLOBALS。前面的例子可以重寫為： @@ -414,13 +295,7 @@ echo $b; - The $GLOBALS array is an associative array with - the name of the global variable being the key and the contents of - that variable being the value of the array element. - Notice how $GLOBALS exists in any scope, this - is because $GLOBALS is a superglobal. - Here's an example demonstrating the power of superglobals: + $GLOBALS 是一個關聯陳列 (associative array)，全域變數的名即為索引鍵，而該變數的內容即為陳列的值。有否留意到 $GLOBALS 在任何一個範圍都出現？那是因為 $GLOBALS 是一個superglobal。這是一個示範 superglobals 強大功能的例子： @@ -448,11 +323,7 @@ function test_global() - Another important feature of variable scoping is the - static variable. A static variable exists - only in a local function scope, but it does not lose its value - when program execution leaves this scope. Consider the following - example: + 變數範圍的另一個重要功能為靜態變數。靜態變數只在本域函數範圍內存在，但是當程式執行離開此範圍時，它並不會喪失它的值。看看下面的例子： @@ -471,13 +342,7 @@ function Test () - This function is quite useless since every time it is called it - sets $a to 0 and prints - "0". The $a++ which increments the - variable serves no purpose since as soon as the function exits the - $a variable disappears. To make a useful - counting function which will not lose track of the current count, - the $a variable is declared static: + 此函數沒有什麼用處，因每一次執行它時，它將 $a 設為 0 然後列印出 "0"。$a++ 增加了 $a 的值，但並沒有實際用途因為一旦離開了該函數，變數 $a 也隨之消失。要設計一個有用的、不會丟失當前計數的計數函數，我們可以將 $a宣佈為靜態： @@ -496,18 +361,11 @@ function Test() - Now, every time the Test() function is called it will print the - value of $a and increment it. + 現在，每當函數 Test() 被呼叫時，它會列印出 $a 的值，然後加上一。 - Static variables also provide one way to deal with recursive - functions. A recursive function is one which calls itself. Care - must be taken when writing a recursive function because it is - possible to make it recurse indefinitely. You must make sure you - have an adequate way of terminating the recursion. The following - simple function recursively counts to 10, using the static - variable $count to know when to stop: + 靜態變數也提供一種處理遞迴函數的方法。遞迴函數是一種呼叫自己的函數。編寫遞迴函數時必須留意，因為若編寫錯誤，它有可能會無定限地遞迴。您必須確定足夠的方式來終止遞迴。下列簡單的函數將遞迴地數到 10，利用靜態變數 $count 來斷定什麼時候停止： @@ -531,12 +389,7 @@ function Test() - The Zend Engine 1, driving PHP4, implements the - static and global modifier for - variables in terms of references. For example, a true global variable - imported inside a function scope with the global - statement actually creates a reference to the global variable. This can - lead to unexpected behaviour which the following example addresses: + 驅動 PHP 4 的 Zend Engine 1 是以參照的方式來實現 static 和 global 的。例如，一個真正的全域變數使用 global 方式引進一個函數範圍時實際上就是建立了一個全域變數的參照。這將導致一些意想不到的行為，正如下列例子所述： @@ -563,7 +416,7 @@ var_dump($obj); - Executing this example will result in the following output: + 執行這個例子將會導致下列的輸出： @@ -573,8 +426,7 @@ object(stdClass)(0) { - A similar behaviour applies to the static statement. - References are not stored statically: + static 陳述式也會導致同樣的輸出。參照並沒有被靜態地儲存： @@ -618,7 +470,7 @@ $still_obj2 = get_instance_noref(); - Executing this example will result in the following output: + 執行此例子將導致下列的輸出： @@ -633,21 +485,17 @@ Static object: object(stdClass)(1) { - This example demonstrates that when assigning a reference to a static - variable, it's not remembered when you call the - &get_instance_ref() function a second time. + 上述例子示範了在指派一個參照給予一個靜態變數後，當您第二次呼叫 &get_instance_ref() 函數時，它是不會記住之前的值的。 - Variable variables + 可變變數 - Sometimes it is convenient to be able to have variable variable - names. That is, a variable name which can be set and used - dynamically. A normal variable is set with a statement such as: + 有時候，可以使用可變變數會令到工作更加方便。也就是就，一個變數的名可以被動態的設定和使用。一個普通的變數是以下列的方法設定： @@ -661,10 +509,7 @@ $a = "hello"; - A variable variable takes the value of a variable and treats that - as the name of a variable. In the above example, - hello, can be used as the name of a variable - by using two dollar signs. i.e. + 一個可變變數是以另一個變數的值作為它的變數名。在上述例子中，只要加兩個 $ 在 hello 的前面就可把它當作是一個變數的名來使用了。即： @@ -678,10 +523,7 @@ $$a = "world"; - At this point two variables have been defined and stored in the - PHP symbol tree: $a with contents "hello" and - $hello with contents "world". Therefore, this - statement: + 這時，有兩個變數被定義然後儲存在 PHP 的符號表中：含有 "hello" 的 $a 及含有 "world" 的 $hello。所以，此敘述： @@ -695,7 +537,7 @@ echo "$a ${$a}"; - produces the exact same output as: + 與下列這句有著同樣的輸出： @@ -709,48 +551,34 @@ echo "$a $hello"; - i.e. they both produce: hello world. + 即，它們都輸出：hello world。 - In order to use variable variables with arrays, you have to - resolve an ambiguity problem. That is, if you write - $$a[1] then the parser needs to know if you - meant to use $a[1] as a variable, or if you - wanted $$a as the variable and then the [1] - index from that variable. The syntax for resolving this ambiguity - is: ${$a[1]} for the first case and - ${$a}[1] for the second. + 為了要在陳列中使用可變變數，您必須首先解決一個模糊的問題。比方說，如果您使用 $$a[1]，那剖析器必須知道您是想當 $a[1] 是變數來使用，還是當 $$a 是變數，然後指向那個變數的第 [1] 個索引。解決上述模糊問題的語法是：第一個情況使用 ${$a[1]}、第二個情況使用 ${$a}[1]。 - Please note that variable variables cannot be used with PHP's - Superglobal arrays. - This means you cannot do things like ${$_GET}. If you are - looking for a way to handle availability of superglobals and the old - HTTP_*_VARS, you might want to try - referencing them. + 必須留意的是，可變變數是不能使用於 PHP 的 Superglobal 陳列。這表示您不能使用 ${$_GET} 這樣的敘述。如果您真的想使用 superglobals 和舊的 HTTP_*_VARS，您可以嘗試以參照的方式使用。 - Variables from outside PHP + 來自 PHP 以外的變數 - HTML Forms (GET and POST) + HTML 表單 (GET 和POST) - When a form is submitted to a PHP script, the information from - that form is automatically made available to the script. There - are many ways to access this information, for example: + 當一份表單傳送給 PHP 程式時，表單內的資訊將自動提供給該程式。我們有很多方法存取這些資訊，範例： - A simple HTML form + 一個簡單的 HTML 表單 @@ -764,13 +592,12 @@ echo "$a $hello"; - Depending on your particular setup and personal preferences, there - are many ways to access data from your HTML forms. Some examples are: + 根據您的安裝方式和個人偏好，PHP 提供多種方式存取 HTML 表單中的資料。一些例子如： - Accessing data from a simple POST HTML form + 存取一個以 POST 方式傳送的簡單 HTML 表單 - Using a GET form is similar except you'll use the appropriate - GET predefined variable instead. GET also applies to the - QUERY_STRING (the information after the '?' in an URL). So, - for example, http://www.example.com/test.php?id=3 - contains GET data which is accessible with $_GET['id']. - See also $_REQUEST and - import_request_variables. + 使用 GET 方式傳送的表單用法類似，只不過使用合適的先前定義的函數。GET 也可使用在查詢字串 (QUERY_STRING) 〈URL 中問號 '?' 後面的資訊〉。例如，http://www.example.com/test.php?id=3 含有以 $_GET['id'] 方式存取的 GET 資料。請參考 $_REQUEST 和 import_request_variables()。 - Superglobal arrays, - like $_POST and $_GET, became - available in PHP 4.1.0 + Superglobal 陳列如 $_POST 及 $_GET 在 PHP 版本 4.1.0 以上才開始提供。 - As shown, before PHP 4.2.0 the default value for register_globals - was on. And, in PHP 3 it was always on. The PHP - community is encouraging all to not rely on this directive - as it's preferred to assume it's off and code - accordingly. + 上面提到，在 PHP 4.2.0 之前的版本中，register_globals 的預設值是 on。而在 PHP 3 中，它永遠是 on 的。我們建議所有使用者不要依賴此指令，並在編寫時將它當作是 off 來設計您的程式。 - The magic_quotes_gpc - configuration directive affects Get, Post and Cookie values. If - turned on, value (It's "PHP!") will automagically become (It\'s \"PHP!\"). - Escaping is needed for DB insertion. See also - addslashes, stripslashes and - magic_quotes_sybase. + magic_quotes_gpc 組態指令會影響到 Get，Post 和 Cookie 的值。如果開啟此指令，(It's "PHP!") 的值將變成 (It\'s \"PHP!\")。此跳出工作在將字串插入資料庫前是必須要做的。請參考 addslashes，stripslashes 和 magic_quotes_sybase。 - PHP also understands arrays in the context of form variables - (see the related faq). You may, - for example, group related variables together, or use this - feature to retrieve values from a multiple select input. For - example, let's post a form to itself and upon submission display - the data: + PHP 也懂得處理陳列式的表單變數〈請參觀相關的 FAQ〉。您可以將相關的變數歸類，或用此功能來取回多元選擇輸入表單的值。在下列範例中，我們將表單張貼到它自己，並在傳送後把資料顯示出來： + - More complex form variables + 更複雜的表單變數 - In PHP 3, the array form variable usage is limited to - single-dimensional arrays. In PHP 4, no such restriction applies. + PHP 3 的陳列表單變數只可以使用一維陳列，而 PHP 4 則沒有此限制。 - IMAGE SUBMIT variable names + IMAGE SUBMIT 變數名稱 - When submitting a form, it is possible to use an image instead - of the standard submit button with a tag like: + 在傳送表單時，我們可以使用下列標籤將標準的提交鍵以圖像來取代： @@ -901,13 +704,7 @@ if ($HTTP_POST_VARS['action'] == 'submitted') { - When the user clicks somewhere on the image, the accompanying - form will be transmitted to the server with two additional - variables, sub_x and sub_y. These contain the coordinates of the - user click within the image. The experienced may note that the - actual variable names sent by the browser contains a period - rather than an underscore, but PHP converts the period to an - underscore automatically. + 當使用者在圖像的任何一處按一下，伴隨的表單就會傳送到伺服器，隨其而來還附加了兩個變數，sub_x 和 sub_y。這包含了使用者按在圖像的座標。有經驗的使用者或許知道由瀏覽器傳送來的變數名稱應該包含句號，而不是底線，但 PHP 自動地將句號轉換成為底線。 @@ -917,24 +714,12 @@ if ($HTTP_POST_VARS['action'] == 'submitted') { HTTP Cookies - PHP transparently supports HTTP cookies as defined by Netscape's Spec. Cookies are a - mechanism for storing data in the remote browser and thus - tracking or identifying return users. You can set cookies using - the setcookie function. Cookies are part of - the HTTP header, so the SetCookie function must be called before - any output is sent to the browser. This is the same restriction - as for the header function. Cookie data - is then available in the appropriate cookie data arrays, such - as $_COOKIE, $HTTP_COOKIE_VARS - as well as in $_REQUEST. See the - setcookie manual page for more details and - examples. + PHP 絕對支援 Netscape規格的 HTTP cookies。Cookies 是用來將資料儲存在用戶端的瀏覽器中，以便日後追蹤或識別返回的使用者。您可以用 setcookie() 函數來設定 cookies。Cookies 是 HTTP header 的一部份，因此 SetCookie 函數一定要在任何資料傳送去瀏覽器前呼叫。這和 header() 函數有著相同的限定。Cookie 資料可以在 $_COOKIE，$HTTP_COOKIE_VARS 及 $_REQUEST 陳列中供使用。詳情和範例請參考手冊的 setcookie() 部份。 - If you wish to assign multiple values to a single cookie variable, you - may assign it as an array. For example: + 若您要將多個值指派給一個 cookie 變數，那您就要使用陳列來指派了。範例： @@ -949,21 +734,15 @@ if ($HTTP_POST_VARS['action'] == 'submitted') { - That will create two seperate cookies although MyCookie will now - be a single array in your script. If you want to set just one cookie - with multiple values, consider using serialize or - explode on the value first. + 這將會建立兩個個別的 cookies，儘管現在 MyCookie在您的程式中是一個單元陳列。如果您要以一個 cookie 建立多個值，那您可先對那些值使用 serialize() 或 explode() 函數。 - Note that a cookie will replace a previous cookie by the same - name in your browser unless the path or domain is different. So, - for a shopping cart application you may want to keep a counter - and pass this along. i.e. + 有一點必須留意的是，一個 cookie 將會替代瀏覽器中另一個同名的 cookie，除非該 cookie 的路徑或網域名稱不同。所以，在設計購物車程式時，您最好保持一個計數器，並將此數據傳遞下去，即： - A <function>setcookie</function> example + 一個 <function>setcookie()</function> 的範例 - Dots in incoming variable names + 在變數名字中的句號 (dots) - Typically, PHP does not alter the names of variables when they - are passed into a script. However, it should be noted that the - dot (period, full stop) is not a valid character in a PHP - variable name. For the reason, look at it: + 一般上，PHP 並不會更改傳入程式的變數名稱。然而，您必須留意句號 (.) 並不是一個有效的 PHP 變數名稱字元，正如： + ]]> - Now, what the parser sees is a variable named - $varname, followed by the string concatenation - operator, followed by the barestring (i.e. unquoted string which - doesn't match any known key or reserved words) 'ext'. Obviously, - this doesn't have the intended result. + 這時，剖析器見到的只是一個叫做 $varname 的變數，跟隨著字串連結運算子 (.)，再來是一個無引號的字串：ext。顯然地，這並不會帶來您想要的結果。 - For this reason, it is important to note that PHP will - automatically replace any dots in incoming variable names with - underscores. + 正因如此，PHP 會自動的將傳入的變數名稱中的句號 (.) 改為底線 (_)。 - Determining variable types + 判定變數的類型 - Because PHP determines the types of variables and converts them - (generally) as needed, it is not always obvious what type a given - variable is at any one time. PHP includes several functions - which find out what type a variable is, such as: - gettype, is_array, - is_float, is_int, - is_object, and - is_string. See also the chapter on - Types. + 由於 PHP 會自行判斷變數的類型，並按需要轉變它們的類型，因此有時也難以明顯地判定一個變數在某個時刻的類型。有鑑於此，PHP 提供了幾個判定變數類型的函數：gettype()、is_array()、is_float()、is_int()、is_object() 及 is_string()。請參閱類型一章。 @@ -1046,4 +809,4 @@ End: vim600: syn=xml fen fdm=syntax fdl=2 si vim: et tw=78 syn=sgml vi: ts=1 sw=1 ---> +--> \ No newline at end of file