difference between call by value and call by reference in php and also $$ means?

(1) I want to know what is the difference between call by value and call by reference in php . PHP works on call by value or call by reference? (2) And also i want to know that do you mean by $$ sign in php For example:- $a = 'name'; $$a = "Paul"; echo $name; output is Paul As above example what do u mean by $$ on PHP. $$a = b; in PHP means "take the value of $a , and set the vari

价值调用和php中的引用调用之间的区别,还有$$意味着什么?

(1)我想知道在值中调用和在php通过引用调用之间有什么区别。 PHP是按价值调用还是按引用调用? (2)而且我想知道你的意思是由$$在$ php登录 例如:- $a = 'name'; $$a = "Paul"; echo $name; output is Paul 如上例所示,你在PHP上用$$表示什么。 $$a = b; 在PHP中意味着“取$a的值,并将名称为该值的变量设置为等于b ”。 换一种说法: $foo = "bar"; $$foo = "baz"; echo $bar; // outputs 'baz' 但是,请看看

Double dollar sign php

Possible Duplicate: What does $$ (dollar dollar or double dollar) mean in PHP? I found myself using this kind of code in one of my controllers: foreach(get_object_vars($this->view) as $property=>$value){ $$property = $value; } Is there any problem with using the $$property to "localize" view properties into simple $variables? edit: I should add that this code is run i

双美元符号的PHP

可能重复: PHP(美元美元或双倍美元)在PHP中意味着什么? 我发现自己在我的一个控制器中使用了这种代码: foreach(get_object_vars($this->view) as $property=>$value){ $$property = $value; } 使用$$属性将视图属性“本地化”为简单的$变量有什么问题吗? 编辑: 我应该补充说,这段代码是在特定于视图的方法的范围内运行的,所以不会覆盖局部变量。 这是为了让你们中的一些人指出重写局部变量的问题。

Are there pointers in php?

What does this code mean? Is this how you declare a pointer in php? $this->entryId = $entryId; Variable names in PHP start with $ so $entryId is the name of a variable. $this is a special variable in Object Oriented programming in PHP, which is reference to current object. -> is used to access an object member (like properties or methods) in PHP, like the syntax in C++. so your code m

在PHP中有指针吗?

这个代码是什么意思? 这是你如何在PHP中声明一个指针? $this->entryId = $entryId; PHP中的变量名称以$开头,因此$ entryId是变量的名称。 $这是PHP中面向对象编程中的一个特殊变量,它是对当前对象的引用。 - >用于访问PHP中的对象成员(如属性或方法),就像C ++中的语法一样。 所以你的代码意味着这个: 将变量$ entryId的值放入此对象的entryId字段(或属性)中。 PHP中的&运算符表示传递引用。 这里是

php $$ operator

Possible Duplicate: What does $$ mean in PHP? I can't find documentation for this anywhere. You'd think it would be easy! I came across this piece of code when reading through a webmail client framework (favourite pass time hobby) and i dont know what $$ means... if (isset($_POST)){ while ( list($var, $val) = each($_POST) ) $$var = input_filter($var,$val); } Could somebody also e

php $$操作符

可能重复: $$在PHP中意味着什么? 我找不到任何地方的文档。 你会认为这很容易! 在阅读webmail客户端框架(最喜欢的通行时间爱好)时,我遇到了这段代码,我不知道$$意味着什么... if (isset($_POST)){ while ( list($var, $val) = each($_POST) ) $$var = input_filter($var,$val); } 有人可以基本解释这是什么吗? 我的解释是 if post is set loop until end of $_POST initialise each $_POST as a

What is $$ in php?

Possible Duplicate: What does $$ mean in PHP? Double dollar sign php What is $$ in php. This question is asked in a recent interview for a web developer position. Thanks in advance! This is a variable variable. They work by using a variable to contain the name of another variable like so: $var = 'test'; $test = 'echod variable'; echo $$var; // output echod variable It's a variabl

PHP中的$$是什么?

可能重复: $$在PHP中意味着什么? 双美元符号的PHP 什么是PHP中的$$。 在最近的一次采访中,这个问题是针对Web开发人员的。 提前致谢! 这是一个变量变量。 他们通过使用变量来包含另一个变量的名称,如下所示: $var = 'test'; $test = 'echod variable'; echo $$var; // output echod variable 这是一个变量变量: 有时能够具有可变变量名称很方便。 即,可以动态设置和使用的变量名称。 动态变量名称,

Why are there two $$ signs infront of variable?

Possible Duplicate: what does $$ mean in PHP? I recently needed to make a change on a application and came across this $pageObject->createPageContent($$templateName); The method looked like this function createPageContent($page_content_html) { $this->page_content = $page_content_html; } My question is when I removed the one $ sign infront of the variable I got a differen

为什么在变量的前面有两个$$符号?

可能重复: $$在PHP中意味着什么? 我最近需要对应用程序进行更改,并且遇到了这个$pageObject->createPageContent($$templateName); 该方法看起来像这样 function createPageContent($page_content_html) { $this->page_content = $page_content_html; } 我的问题是,当我删除变量的一个$符号时,我得到了与双重$ $$不同的结果。 为什么有一个$符号额外? 这是什么目的? $$表示PHP中的一个变量

What does $$ in php mean?

This question already has an answer here: What does $$ (dollar dollar or double dollar) mean in PHP? 6 answers In PHP, $$ means you are about to inflict years of pain and suffering on at least one maintenance programmer. Note that you might wind up being that maintenance programmer. It is a variable variable. Imagine this: $quux = 'bar'; $foo[$quux] = "baz"; echo $foo['bar']; //prints b

$$在php中是什么意思?

这个问题在这里已经有了答案: PHP(美元美元或双倍美元)在PHP中意味着什么? 6个答案 在PHP中, $$意味着您至少会在一位维护程序员中造成多年的痛苦和痛苦。 请注意,您可能最终成为该维护程序员。 它是一个变量变量。 想象一下: $quux = 'bar'; $foo[$quux] = "baz"; echo $foo['bar']; //prints baz 如果没有数组这样的东西,你可以尝试这样的事情: $quux = 'bar'; $$quux = "baz"; echo $bar; //prints baz

i got this PHP question from my friend about variable dollar sign

Possible Duplicate: what does $$ mean in PHP? what is the different between $thisvariable and $$thisvariable. as you notice, the first variable has one dollar sign while the second got two dollar signs. $variable is a variable and $$variable is a variable variables, $my_name = "anthony"; // variable $my_name echo $my_name; // outputs "anthony" $a_var = "my_name"; // assigning literal to

我从我的朋友那里得到了有关可变美元符号的这个PHP问题

可能重复: $$在PHP中意味着什么? $ thisvariable和$$这个变量之间有什么不同。 正如你注意到的那样,第一个变量有一个美元符号,而第二个变量有两个美元符号。 $variable是一个变量, $$variable是一个变量变量, $my_name = "anthony"; // variable $my_name echo $my_name; // outputs "anthony" $a_var = "my_name"; // assigning literal to variable $a_var echo $$a_var; // outputs "anthony" 这可能有点令

What is the difference between $a and $$a in php?

Possible Duplicate: What does $$ mean in PHP? I am new to PHP and I don't know what the difference between $a and $$a is. If $a = 'b' then $$a is $b . This is a variable variable. They are evil. Use arrays instead (which do the same thing, but more maintainably and with the ability to use array functions on them). $a represents a variable $$a represents a variable with t

$ a和$$ a在php中有什么区别?

可能重复: $$在PHP中意味着什么? 我是PHP的新手,我不知道$a和$$a之间的区别是什么。 如果$a = 'b'那么$$a是$b 。 这是一个变量变量。 他们是邪恶的。 使用数组(而不是相同的东西,但更可维护,并有能力使用数组函数)。 $a代表一个变量 $$a表示内容为$a的变量 例: $test = "hello world"; $a = "test"; echo $$a; 输出将是hello world $a是变量a的内容, $$a是以$a命名的变量的内容。 不要在

PHP script not passing url with a array variable

This code is not passing URL to make topic clickable main problem is in third line after while loop. I got this error : Parse error: syntax error, unexpected 'id' (T_STRING), expecting ',' or ';' in D:xmapphtdocsforummain_forum.php on line 37 Code : while($rows=mysql_fetch_array($result)) { echo "<tr>"; echo "<td align='center' bgcolor=#FFFFFF>",$rows['id'],"</td>";

PHP脚本不传递数组变量的URL

此代码不传递URL来使主题可点击的主要问题在while循环后的第三行。 我得到这个错误: Parse error: syntax error, unexpected 'id' (T_STRING), expecting ',' or ';' in D:xmapphtdocsforummain_forum.php on line 37 代码: while($rows=mysql_fetch_array($result)) { echo "<tr>"; echo "<td align='center' bgcolor=#FFFFFF>",$rows['id'],"</td>"; echo "<td bgcolor='#FFFFFF'>",