Static Function Variables and Concatenation in PHP
Consider the following:
$var = 'foo' . 'bar'; # Not a member of a class, free-standing or in a function.
As soon as I mark $var as static, however:
static $var = 'foo' . 'bar';
PHP (5.3.1 on a WAMP setup) complains with the following error:
Parse error: syntax error, unexpected '.', expecting ',' or ';'
It seems that the string concatenation is the culprit here.
What's going on here? Can someone explain the rules for static variables to me?
php string concatenation static-variables
asked Feb 12 '11 at 6:33
jklanders
8814
add a comment |
Consider the following:
$var = 'foo' . 'bar'; # Not a member of a class, free-standing or in a function.
As soon as I mark $var as static, however:
static $var = 'foo' . 'bar';
PHP (5.3.1 on a WAMP setup) complains with the following error:
Parse error: syntax error, unexpected '.', expecting ',' or ';'
It seems that the string concatenation is the culprit here.
What's going on here? Can someone explain the rules for static variables to me?
php string concatenation static-variables
asked Feb 12 '11 at 6:33
jklanders
8814
add a comment |
Consider the following:
$var = 'foo' . 'bar'; # Not a member of a class, free-standing or in a function.
As soon as I mark $var as static, however:
static $var = 'foo' . 'bar';
PHP (5.3.1 on a WAMP setup) complains with the following error:
Parse error: syntax error, unexpected '.', expecting ',' or ';'
It seems that the string concatenation is the culprit here.
What's going on here? Can someone explain the rules for static variables to me?
php string concatenation static-variables
asked Feb 12 '11 at 6:33
jklanders
8814
Consider the following:
$var = 'foo' . 'bar'; # Not a member of a class, free-standing or in a function.
As soon as I mark $var as static, however:
static $var = 'foo' . 'bar';
PHP (5.3.1 on a WAMP setup) complains with the following error:
Parse error: syntax error, unexpected '.', expecting ',' or ';'
It seems that the string concatenation is the culprit here.
What's going on here? Can someone explain the rules for static variables to me?
php string concatenation static-variables
php string concatenation static-variables
asked Feb 12 '11 at 6:33
jklanders
8814
asked Feb 12 '11 at 6:33
jklanders
8814
asked Feb 12 '11 at 6:33
jklanders
8814
asked Feb 12 '11 at 6:33
jklanders
8814
asked Feb 12 '11 at 6:33
jklanders
8814
8814
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
The manual states, in Variables scope:
Trying to assign values to these [static] variables which are the result of expressions will cause a parse error.
There is also mention of it in Static keyword:
Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed.
Although it should be noted that a property, static or not, cannot be initialized using an expression neither.
answered Feb 12 '11 at 6:43
netcoder
53k14104132
why is this? How can I do some thing like :public static $model_path=APP_PATH."/models/";
– Hafiz
May 2 '12 at 20:09
1
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time sostatic $foo = "a";orpublic $foo = CONSTANT;works. Expressions, likepublic $foo = 1 + 2;orstatic $foo = 'a' . 'b';are evaluated at runtime.
– netcoder
May 2 '12 at 20:24
1
In your case, you could simply define aMODEL_PATHconstant. Do something like:define('MODEL_PATH', APP_PATH."models/");then use this constant instead in your class:class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.
– netcoder
May 2 '12 at 20:25
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
add a comment |
You can not do expressions in initializers. You can, however, do this:
define('FOOBAR', 'foo'.'bar');
static $var = FOOBAR;
echo $var;
Little known fact is that even though initializers can not contain runtime expressions, it can contain constants which can be defined and resolved at runtime. The constant has to be defined by the time $var is first used though, otherwise you'll get string identical to the constant (e.g. "FOOBAR").
answered Feb 12 '11 at 6:49
StasM
8,33433981
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
add a comment |
I do this:
class MyClass {
static $var1;
static $var2;
public static function _init() {
self::$var1 = 'slkslk' . 'sksks' . 'arbitrary' ;
self::var2 = <<<EOT
<root>
<elem1>skjsksj</elem1>
</root>
EOT;
}
}
MyClass::_init();
answered May 13 '12 at 4:19
Cheeso
134k73404632
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f4976717%2fstatic-function-variables-and-concatenation-in-php%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
The manual states, in Variables scope:
Trying to assign values to these [static] variables which are the result of expressions will cause a parse error.
There is also mention of it in Static keyword:
Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed.
Although it should be noted that a property, static or not, cannot be initialized using an expression neither.
answered Feb 12 '11 at 6:43
netcoder
53k14104132
why is this? How can I do some thing like :public static $model_path=APP_PATH."/models/";
– Hafiz
May 2 '12 at 20:09
1
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time sostatic $foo = "a";orpublic $foo = CONSTANT;works. Expressions, likepublic $foo = 1 + 2;orstatic $foo = 'a' . 'b';are evaluated at runtime.
– netcoder
May 2 '12 at 20:24
1
In your case, you could simply define aMODEL_PATHconstant. Do something like:define('MODEL_PATH', APP_PATH."models/");then use this constant instead in your class:class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.
– netcoder
May 2 '12 at 20:25
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
add a comment |
The manual states, in Variables scope:
Trying to assign values to these [static] variables which are the result of expressions will cause a parse error.
There is also mention of it in Static keyword:
Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed.
Although it should be noted that a property, static or not, cannot be initialized using an expression neither.
answered Feb 12 '11 at 6:43
netcoder
53k14104132
why is this? How can I do some thing like :public static $model_path=APP_PATH."/models/";
– Hafiz
May 2 '12 at 20:09
1
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time sostatic $foo = "a";orpublic $foo = CONSTANT;works. Expressions, likepublic $foo = 1 + 2;orstatic $foo = 'a' . 'b';are evaluated at runtime.
– netcoder
May 2 '12 at 20:24
1
In your case, you could simply define aMODEL_PATHconstant. Do something like:define('MODEL_PATH', APP_PATH."models/");then use this constant instead in your class:class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.
– netcoder
May 2 '12 at 20:25
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
add a comment |
The manual states, in Variables scope:
Trying to assign values to these [static] variables which are the result of expressions will cause a parse error.
There is also mention of it in Static keyword:
Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed.
Although it should be noted that a property, static or not, cannot be initialized using an expression neither.
answered Feb 12 '11 at 6:43
netcoder
53k14104132
The manual states, in Variables scope:
Trying to assign values to these [static] variables which are the result of expressions will cause a parse error.
There is also mention of it in Static keyword:
Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed.
Although it should be noted that a property, static or not, cannot be initialized using an expression neither.
answered Feb 12 '11 at 6:43
netcoder
53k14104132
answered Feb 12 '11 at 6:43
netcoder
53k14104132
answered Feb 12 '11 at 6:43
netcoder
53k14104132
answered Feb 12 '11 at 6:43
netcoder
53k14104132
53k14104132
why is this? How can I do some thing like :public static $model_path=APP_PATH."/models/";
– Hafiz
May 2 '12 at 20:09
1
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time sostatic $foo = "a";orpublic $foo = CONSTANT;works. Expressions, likepublic $foo = 1 + 2;orstatic $foo = 'a' . 'b';are evaluated at runtime.
– netcoder
May 2 '12 at 20:24
1
In your case, you could simply define aMODEL_PATHconstant. Do something like:define('MODEL_PATH', APP_PATH."models/");then use this constant instead in your class:class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.
– netcoder
May 2 '12 at 20:25
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
add a comment |
why is this? How can I do some thing like :public static $model_path=APP_PATH."/models/";
– Hafiz
May 2 '12 at 20:09
1
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time sostatic $foo = "a";orpublic $foo = CONSTANT;works. Expressions, likepublic $foo = 1 + 2;orstatic $foo = 'a' . 'b';are evaluated at runtime.
– netcoder
May 2 '12 at 20:24
1
In your case, you could simply define aMODEL_PATHconstant. Do something like:define('MODEL_PATH', APP_PATH."models/");then use this constant instead in your class:class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.
– netcoder
May 2 '12 at 20:25
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
why is this? How can I do some thing like :
public static $model_path=APP_PATH."/models/";– Hafiz
May 2 '12 at 20:09
why is this? How can I do some thing like :
public static $model_path=APP_PATH."/models/";– Hafiz
May 2 '12 at 20:09
1
1
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time so
static $foo = "a"; or public $foo = CONSTANT; works. Expressions, like public $foo = 1 + 2; or static $foo = 'a' . 'b'; are evaluated at runtime.– netcoder
May 2 '12 at 20:24
@Hafiz: You can't, because these are evaluated at compile-time. Constants and string literals are evaluated at compile-time so
static $foo = "a"; or public $foo = CONSTANT; works. Expressions, like public $foo = 1 + 2; or static $foo = 'a' . 'b'; are evaluated at runtime.– netcoder
May 2 '12 at 20:24
1
1
In your case, you could simply define a
MODEL_PATH constant. Do something like: define('MODEL_PATH', APP_PATH."models/"); then use this constant instead in your class: class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.– netcoder
May 2 '12 at 20:25
In your case, you could simply define a
MODEL_PATH constant. Do something like: define('MODEL_PATH', APP_PATH."models/"); then use this constant instead in your class: class Foo { public static $model_path = MODEL_PATH; }. Either that, or initialize them in the constructor or initialization method.– netcoder
May 2 '12 at 20:25
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
I appreciate your reply but this way I will be such paths one thing at 2 places every time :| . May be I should use constant at all those places where I am using static variables with expressions.
– Hafiz
May 2 '12 at 20:47
add a comment |
You can not do expressions in initializers. You can, however, do this:
define('FOOBAR', 'foo'.'bar');
static $var = FOOBAR;
echo $var;
Little known fact is that even though initializers can not contain runtime expressions, it can contain constants which can be defined and resolved at runtime. The constant has to be defined by the time $var is first used though, otherwise you'll get string identical to the constant (e.g. "FOOBAR").
answered Feb 12 '11 at 6:49
StasM
8,33433981
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
add a comment |
You can not do expressions in initializers. You can, however, do this:
define('FOOBAR', 'foo'.'bar');
static $var = FOOBAR;
echo $var;
Little known fact is that even though initializers can not contain runtime expressions, it can contain constants which can be defined and resolved at runtime. The constant has to be defined by the time $var is first used though, otherwise you'll get string identical to the constant (e.g. "FOOBAR").
answered Feb 12 '11 at 6:49
StasM
8,33433981
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
add a comment |
You can not do expressions in initializers. You can, however, do this:
define('FOOBAR', 'foo'.'bar');
static $var = FOOBAR;
echo $var;
Little known fact is that even though initializers can not contain runtime expressions, it can contain constants which can be defined and resolved at runtime. The constant has to be defined by the time $var is first used though, otherwise you'll get string identical to the constant (e.g. "FOOBAR").
answered Feb 12 '11 at 6:49
StasM
8,33433981
You can not do expressions in initializers. You can, however, do this:
define('FOOBAR', 'foo'.'bar');
static $var = FOOBAR;
echo $var;
Little known fact is that even though initializers can not contain runtime expressions, it can contain constants which can be defined and resolved at runtime. The constant has to be defined by the time $var is first used though, otherwise you'll get string identical to the constant (e.g. "FOOBAR").
answered Feb 12 '11 at 6:49
StasM
8,33433981
answered Feb 12 '11 at 6:49
StasM
8,33433981
answered Feb 12 '11 at 6:49
StasM
8,33433981
answered Feb 12 '11 at 6:49
StasM
8,33433981
8,33433981
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
add a comment |
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
mean I must need to define every thing as constant if I need to concatenate any thing? Mean every single initialization will take 2 steps?
– Hafiz
May 2 '12 at 20:10
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
Not every single one, just ones where you need to use expressions.
– StasM
May 3 '12 at 6:56
add a comment |
I do this:
class MyClass {
static $var1;
static $var2;
public static function _init() {
self::$var1 = 'slkslk' . 'sksks' . 'arbitrary' ;
self::var2 = <<<EOT
<root>
<elem1>skjsksj</elem1>
</root>
EOT;
}
}
MyClass::_init();
answered May 13 '12 at 4:19
Cheeso
134k73404632
add a comment |
I do this:
class MyClass {
static $var1;
static $var2;
public static function _init() {
self::$var1 = 'slkslk' . 'sksks' . 'arbitrary' ;
self::var2 = <<<EOT
<root>
<elem1>skjsksj</elem1>
</root>
EOT;
}
}
MyClass::_init();
answered May 13 '12 at 4:19
Cheeso
134k73404632
add a comment |
I do this:
class MyClass {
static $var1;
static $var2;
public static function _init() {
self::$var1 = 'slkslk' . 'sksks' . 'arbitrary' ;
self::var2 = <<<EOT
<root>
<elem1>skjsksj</elem1>
</root>
EOT;
}
}
MyClass::_init();
answered May 13 '12 at 4:19
Cheeso
134k73404632
I do this:
class MyClass {
static $var1;
static $var2;
public static function _init() {
self::$var1 = 'slkslk' . 'sksks' . 'arbitrary' ;
self::var2 = <<<EOT
<root>
<elem1>skjsksj</elem1>
</root>
EOT;
}
}
MyClass::_init();
answered May 13 '12 at 4:19
Cheeso
134k73404632
answered May 13 '12 at 4:19
Cheeso
134k73404632
answered May 13 '12 at 4:19
Cheeso
134k73404632
answered May 13 '12 at 4:19
Cheeso
134k73404632
134k73404632
add a comment |
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f4976717%2fstatic-function-variables-and-concatenation-in-php%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
