用戶(hù)評(píng)論:

[#1]

cnbk201 at gmail dot com [2015-01-12 22:07:20]

Small?note?to?consider?in?heredoc?multiple?dimension?array?will?not?work?and?neither?will?any?native?language?functions

$a[1]?="man";$b['man']?="player";

echo?<<

substr($a[1],?1)?//?will?result?in?substr(man,?1)

ED;

?>

[#2]

Anonymous [2014-03-31 15:33:45]

$my_int?=?"12,140";

echo??1?+?$my_int?;

Returns?13?not?the?expected?12141

[#3]

Ray.Paseur often uses Gmail [2014-03-08 13:14:16]

In?Example?#8,?above,?consider?the?risk?to?the?script?if?a?programmer?were?to?define('koolaid1',?'XYZ');??For?this?reason?it's?wise?to?use?quotes?around?literal-string?associative?array?keys.??As?written?without?quotes,?PHP?should?raise?a?Notice.

[#4]

benl39 at free dot fr [2014-03-04 09:14:24]

Note?that?:

<?phpecho 'error'==0,'
';//?TRUEecho'error'=='0','
';//?FALSEecho'0'==0,'
';//?TRUE

//?So,?'error'?!=?'error'???>

[#5]

necrodust44 at gmail dot com [2014-03-04 01:52:28]

String?conversion?to?numbers.

Unfortunately,?the?documentation?is?not?correct.

?The?value?is?given?by?the?initial?portion?of?the?string.?If?the?string?starts?with?valid?numeric?data,?this?will?be?the?value?used.?Otherwise,?the?value?will?be?0?(zero).?

It?is?not?said?and?is?not?shown?in?examples?throughout?the?documentation?that,?while?converting?strings?to?numbers,?leading?space?characters?are?ignored,?like?with?the?strtod?function.

However,?PHP's?behaviour?differs?even?from?the?strtod's.?The?documentation?says?that?if?the?string?contains?a?"e"?or?"E"?character,?it?will?be?parsed?as?a?float,?and?suggests?to?see?the?manual?for?strtod?for?more?information.?The?manual?says

?A?hexadecimal?number?consists?of?a?"0x"?or?"0X"?followed?by?a?nonempty?sequence?of?hexadecimal?digits?possibly?containing?a?radix?character,?optionally?followed?by?a?binary?exponent.??A?binary?exponent?consists?of?a?'P'?or?'p',?followed?by?an?optional?plus?or?minus?sign,?followed?by?a?nonempty?sequence?of?decimal?digits,?and?indicates?multiplication?by?a?power?of?2.?

But?it?seems?that?PHP?does?not?recognise?the?exponent?or?the?radix?character.

strtod?also?uses?the?current?locale?to?choose?the?radix?character,?but?PHP?ignores?the?locale,?and?the?radix?character?is?always?2E.?However,?PHP?uses?the?locale?while?converting?numbers?to?strings.

With?strtod,?the?current?locale?is?also?used?to?choose?the?space?characters,?I?don't?know?about?PHP.

[#6]

espertalhao04 at hotmail dot com [2013-12-10 10:34:09]

gtisza?at?gmail?dot?com

You?incorrectly?stated?that?thee?documentation?doesn't?refer?anything?about?the?semicolon?at?the?end?of?the?heredocs?and?nowdocs??being?interpreted?as?a?"real"?semicolon.

If?you?read?carefully,?you?will?notice?this,?in?the?1st?sentence?of?the?warning?about?heredocs:

"It?is?very?important?to?note?that?the?line?with?the?closing?identifier?must?contain?no?other?characters,?except?a?semicolon?(;)."

Interesting...

It?is?refering?about?semicolons...

But?wait,?there?is?more:

http://php.net/manual/en/language.basic-syntax.instruction-separation.php

1st?sentence?says:

"As?in?C?or?Perl,?PHP?requires?instructions?to?be?terminated?with?a?semicolon?at?the?end?of?each?statement."

So,?here?says?that?semicolons?are?statement?separators,?basicly...

So,?if?you?put?a?"real"?semicolon?at?the?end?of?these?examples:

$a=5;$foo="String";$bar=array();$yep=null;$other=func();?>

Why?shouldn't?you?put?at?the?end?of?heredocs?and?nowdocs?

After?all,?a?heredoc?or?a?nowdoc?is?simply?a?string.

You?should?read?more?carefully?the?documentation?first?before?saying?any?comment.

About?serious?questions:

I?didn't?read?all?comments?here,?but?you?can?run?functions?inside?strings?and?heredocs.

And?you?can?even?nest?them?inside?{}

Example:

$f=function($x){$a=func_get_args();unset($a[0]);returncall_user_func_array($x,$a);};$d=0;

echo$b=<<

,"Example",<<

)}NUMBERS;?>

It's?not?pretty,?and?is?hard?to?read,?but?sometimes?it?is?useful?to?confuse?curious?people?(like?minifying?the?code).

Warning:?if?any?function?that?runs?inside?a?string?or?heredoc?gives?a?fatal?error,?the?script?MAY?continue!

[#7]

php at richardneill dot org [2013-02-28 18:20:54]

Leading?zeroes?in?strings?are?(least-surprise)?not?treated?as?octal.

Consider:

$x?=?"0123"??+?0;

$y?=?0123?+?0;

echo?"x?is?$x,?y?is?$y";????//prints??"x?is?123,?y?is?83"

in?other?words:

*?leading?zeros?in?numeric?literals?in?the?source-code?are?interpreted?as?"octal",?c.f.?strtol().

*?leading?zeros?in?strings?(eg?user-submitted?data),?when?cast?(implicitly?or?explicitly)?to?integer?are?ignored,?and?considered?as?decimal,?c.f.?strtod().

[#8]

mcamiano at ncsu dot edu [2012-10-05 14:43:54]

Regarding?the?lack?of?complex?expression?interpolation,?just?assign?an?identity?function?to?a?variable?and?call?it:

function?id($arg)?{?return?$arg;?}

$expr?=?id;

echo?"Field?is:?{$expr(?"1?".?ucfirst('whatzit'))?}";

It?is?slower?due?to?an?additional?function?call,?but?it?does?avoid?the?assignment?of?a?one-shot?temporary?variable.?When?there?are?a?lot?of?very?simple?value?transformations?made?just?for?display?purposes,?it?can?de-clutter?code.

[#9]

Denis R. [2012-06-10 11:01:54]

Hi.

I?noticed?that?the?documentation?does?not?mention?that?when?you?have?an?XML?element?which?contains?a?dash?(-)?in?its?name?can?only?be?accessed?using?the?bracelets?notation.

For?example:

value4element-one

to?access?the?above?'element-one'?using?SimpleXML?you?need?to?use?the?following:

$simpleXMLObj->root->{'element-one'}

to?retrieve?the?value.

Hope?this?helps,

Denis?R.

[#10]

m021 at springtimesoftware dot com [2012-04-01 14:00:09]

Heredoc?literals?delete?any?trailing?space?(tabs?and?blanks)?on?each?line.?This?is?unexpected,?since?quoted?strings?do?not?do?this.?This?is?probably?done?for?historical?reasons,?so?would?not?be?considered?a?bug.

[#11]

gtisza at gmail dot com [2012-01-10 06:32:10]

The?documentation?does?not?mention,?but?a?closing?semicolon?at?the?end?of?the?heredoc?is?actually?interpreted?as?a?real?semicolon,?and?as?such,?sometimes?leads?to?syntax?errors.

This?works:

$foo=?<<

This?does?not:

foo(<<

);//?syntax?error,?unexpected?';'?>

Without?semicolon,?it?works?fine:

foo(<<

);?>

[#12]

sgbeal at googlemail dot com [2011-08-12 04:44:13]

The?docs?say:?"Heredoc?text?behaves?just?like?a?double-quoted?string,?without?the?double?quotes"?but?there?is?a?notable?hidden?exception?to?that?rule:?the?final?newline?in?the?string?(the?one?before?closing?heredoc?token)?is?elided.?i.e.?if?you?have:

$foo?=?<<

a

b

c

EOF;

the?result?is?equivalent?to?"a\nb\nc",?NOT?"a\nb\nc\n"?like?the?docs?imply.

[#13]

Michael [2011-05-09 05:56:29]

Just?want?to?mention?that?if?you?want?a?literal?{?around?a?variable?within?a?string,?for?example?if?you?want?your?output?to?be?something?like?the?following:

{hello,?world}

and?all?that?you?put?inside?the?{}?is?a?variable,?you?can?do?a?double?{{}},?like?this:

$test?=?'hello,?world';

echo?"{{$test}}";

[#14]

Ultimater at gmail dot com [2011-04-27 15:18:51]

If?you?require?a?NowDoc?but?don't?have?support?for?them?on?your?server?--?since?your?PHP?version?is?less?than?PHP?5.3.0?--?and?you?are?in?need?of?a?workaround,?I'd?suggest?using?PHP's?__halt_compiler()?which?is?basically?a?knock-off?of?Perl's?__DATA__?token?if?you?are?familiar?with?it.

Give?this?a?run?to?see?my?suggestion?in?action:

echo?<<

NowDoc?support?for?PHP?<?5.3.0

content="Note?that?I?built?this?code?explicitly?for?the

php.net?documenation?for?demonstrative?purposes."?/>

body{text-align:center;}

table.border{background:#e0eaee;margin:1px?auto;padding:1px;}

table.border?td{padding:5px;border:1px?solid?#8880ff;text-align:left;

background-color:#eee;}

code?::selection{background:#5f5color:white;}

code?::-moz-selection{background:#5f5;color:white;}

a{color:#33a;text-decoration:none;}

a:hover{color:rgb(3,128,252);}

href="http://php.net/manual/en/language.types.string.php#example-77">

Example?#8?Simple?syntax?example

$nowDoc

EOF;

__halt_compiler()//Example?code?snippet?we?want?displayed?on?the?webpage

//note?that?the?compiler?isn't?actually?stopped?until?the?semicolon;<?php

$juices=?array("apple","orange","koolaid1"=>"purple");

echo"He?drank?some$juices[0]juice.".PHP_EOL;

echo"He?drank?some$juices[1]juice.".PHP_EOL;

echo"He?drank?some?juice?made?of$juice[0]s.".PHP_EOL;//?Won't?workecho"He?drank?some$juices[koolaid1]juice.".PHP_EOL;

classpeople{

public$john="John?Smith";

public$jane="Jane?Smith";

public$robert="Robert?Paulsen";

public$smith="Smith";

}$people=?newpeople();

echo"$people->johndrank?some$juices[0]juice.".PHP_EOL;

echo"$people->johnthen?said?hello?to$people->jane.".PHP_EOL;

echo"$people->john's?wife?greeted$people->robert.".PHP_EOL;

echo"$people->robertgreeted?the?two$people->smiths.";//?Won't?work?>

[#15]

dee jay simple 0 0 7 at ge mahl dot com [2011-03-01 12:15:57]

I?recently?discovered?the?joys?of?using?heredoc?with?sprintf?and?positions.?Useful?if?you?want?some?code?to?iterate,?you?can?repeat?placeholders.

return?($foo+$num);

}

functiongetString()?{$foo=?array("California","Oregon","Washington");shuffle($foo);

return$foo[0];

}

functiongetDiv()?{$num=getNumber();$div=sprintf("

%s",getNumber(rand(-5,5))?);

return$div;

}$string=?<<

I?picked:?%2\$d?as?a?number,?

I?also?picked?%2\$d?as?a?number?again?

%3\$s

%3\$s

%3\$s

%3\$s

%3\$s
THESTRING;$returnText=sprintf($string,getString(),getNumber(),getDiv()??);

echo$returnText;?>

Expected?output?of?the?above?code:

I?like?the?state?of?Oregon

I?picked:?15?as?a?number,

I?also?picked?15?as?a?number?again

5

5

5

5

5

[#16]

saamde at gmail dot com [2010-05-27 15:40:58]

Watch?out?for?the?"unexpected?T_SL"?error.??This?appears?to?occur?when?there?is?white?space?just?after?"<<

[#17]

"Sascha Ziemann" [2009-12-17 01:58:54]

Empty?strings?seem?to?be?no?real?strings,?because?they?behave?different?to?strings?containing?data.?Here?is?an?example.

It?is?possible?to?change?a?character?at?a?specific?position?using?the?square?bracket?notation:

$str='0';$str[0]?='a';

echo$str."\n";//?=>?'a'?>

It?is?also?possible?to?change?a?character?with?does?not?exist,?if?the?index?is?"behind"?the?end?of?the?string:

$str='0';$str[1]?='a';

echo$str."\n";//?=>?0a?>

But?if?you?do?that?on?an?empty?string,?the?string?gets?silently?converted?into?an?array:

$str='';$str[0]?='a';

echo$str."\n";//?=>?Array?>

[#18]

shd at earthling dot net [2009-10-20 02:54:24]

If?you?want?a?parsed?variable?surrounded?by?curly?braces,?just?double?the?curly?braces:

$foo="bar";

echo"{{$foo}}";?>

will?just?show?{bar}.?The?{?is?special?only?if?followed?by?the?$?sign?and?matches?one?}.?In?this?case,?that?applies?only?to?the?inner?braces.?The?outer?ones?are?not?escaped?and?pass?through?directly.

[#19]

deminy at deminy dot net [2009-09-16 21:08:16]

Although?current?documentation?says?'A?string?literal?can?be?specified?in?four?different?ways:?...',?actually?there?is?a?fifth?way?to?specify?a?(binary)?string:

The?above?statement?declares?a?binary?string?using?the?'b'?prefix,?which?is?available?since?PHP?5.2.1.?However,?it?will?only?have?effect?as?of?PHP?6.0.0,?as?noted?on?http://www.php.net/manual/en/function.is-binary.php?.

[#20]

Liesbeth [2009-09-03 01:54:58]

If?you?need?to?emulate?a?nowdoc?in?PHP?

A?text?with?'quotes'

and?$$$dollars$$$.

<?php ?$input=ob_get_contents();ob_end_clean();//?Do?what?you?want?with?$inputecho"

".$input."";?>

[#21]

headden at karelia dot ru [2009-06-20 00:43:20]

Here?is?an?easy?hack?to?allow?double-quoted?strings?and?heredocs?to?contain?arbitrary?expressions?in?curly?braces?syntax,?including?constants?and?other?function?calls:

functionc($a,$b)?{?return$a+$b;?}//?Usageecho"pre{$_expr(1+2)}post\n";//?outputs?'pre?3?post'echo"pre{$_expr(qwe)}post\n";//?outputs?'pre?asd?post'echo"pre{$_expr(c($a,$b)+zxc*2)}post\n";//?outputs?'pre?17?post'

//?General?syntax?is?{$_expr(...)}?>

[#22]

cvolny at gmail dot com [2008-12-02 23:43:36]

I?commented?on?a?php?bug?feature?request?for?a?string?expansion?function?and?figured?I?should?post?somewhere?it?might?be?useful:

using?regex,?pretty?straightforward:

<?phpfunctionstringExpand ($subject,?array$vars)?{//?loop?over?$vars?mapforeach?($varsas$name=>$value)?{//?use?preg_replace?to?match?${`$name`}?or?$`$name`$subject=preg_replace(sprintf('/\$\{?%s\}?/',$name),$value,$subject);

}//?return?variable?expanded?stringreturn$subject;

}?>

using?eval()?and?not?limiting?access?to?only?certain?variables?(entire?current?symbol?table?including?[super]globals):

else$delim='__ASDFZXCV1324ZXCV__';//?button?mashing...

//?built?the?eval?code$statement="return?<<

throw?newEvalException($statement);//?return?variable?expanded?stringreturn$result;

}?>

I?hope?that?helps?someone,?but?I?do?caution?against?using?the?eval()?route?even?if?it?is?tempting.??I?don't?know?if?there's?ever?a?truely?safe?way?to?use?eval()?on?the?web,?I'd?rather?not?use?it.

[#23]

Obeliks [2008-11-15 20:21:36]

Expectedly?<?php ?$string[$x]?>?and?<?php ?substr($string,$x,1)?>?will?yield?the?same?result...?normally!

However,?when?you?turn?on?the??Function?Overloading?Feature?(http://php.net/manual/en/mbstring.overload.php),?this?might?not?be?true!

If?you?use?this?Overloading?Feature?with?3rd?party?software,?you?should?check?for?usage?of?the?String?access?operator,?otherwise?you?might?be?in?for?some?nasty?surprises.

[#24]

Salil Kothadia [2008-10-15 01:33:06]

An?interesting?finding?about?Heredoc?"syntax?error,?unexpected?$end".

I?got?this?error?because?I?did?not?use?the?php?close?tag?"?>"?and?I?had?no?code?after?the?heredoc?code.

foo1.php?code?gives?"syntax?error,?unexpected?$end".

But?in?foo2.php?and?foo3.php,?when?you?add?a?php?close?tag?or?when?you?have?some?more?code?after?heredoc?it?works?fine.

Example?Code:

foo1.php

1.?<?php

2.?$str=?<<

4.?spanning?multiple?lines

5.?using?heredoc?syntax.

6.?EOD;

7.

foo2.php

1.?<?php

2.$str=?<<

3.?Example?of?string

4.?spanning?multiple?lines

5.?using?heredoc?syntax.

6.?EOD;

7.

8.?echo$str;

9.

foo3.php

1.?<?php

2.$str=?<<

3.?Example?of?string

4.?spanning?multiple?lines

5.?using?heredoc?syntax.

6.?EOD;

7.??>

[#25]

steve at mrclay dot org [2008-09-30 13:33:30]

Simple?function?to?create?human-readably?escaped?double-quoted?strings?for?use?in?source?code?or?when?debugging?strings?with?newlines/tabs/etc.

for?($i=0,$l=strlen($str);$i

if?($o<31||$o>126)?{

switch?($o)?{

case9:$ret.='\t';?break;

case10:$ret.='\n';?break;

case11:$ret.='\v';?break;

case12:$ret.='\f';?break;

case13:$ret.='\r';?break;

default:$ret.='\x'.str_pad(dechex($o),2,'0',STR_PAD_LEFT);

}

}?else?{

switch?($o)?{

case36:$ret.='\$';?break;

case34:$ret.='\"';?break;

case92:$ret.='\\\\';?break;

default:$ret.=$str[$i];

}

}

}

return$ret.'"';

}?>

[#26]

chAlx at findme dot if dot u dot need [2008-09-11 08:42:47]

To?save?Your?mind?don't?read?previous?comments?about?dates??;)

When?both?strings?can?be?converted?to?the?numerics?(in?("$a"?>?"$b")?test)?then?resulted?numerics?are?used,?else?FULL?strings?are?compared?char-by-char:

var_dump('1.22'>'01.23');//?bool(false)var_dump('1.22.00'>'01.23.00');//?bool(true)var_dump('1-22-00'>'01-23-00');//?bool(true)var_dump((float)'1.22.00'>?(float)'01.23.00');//?bool(false)?>

[#27]

harmor [2008-09-01 15:05:20]

So?you?want?to?get?the?last?character?of?a?string?using?"String?access?and?modification?by?character"???Well?negative?indexes?are?not?allowed?so?$str[-1]?will?return?an?empty?string.

//Tested?using:?PHP?5.2.5

$str?=?'This?is?a?test.';

$last?=?$str[-1];??????????????????//string(0)?""

$realLast?=?$str[strlen($str)-1];??//string(1)?"."

$substr?=?substr($str,-1);?????????//string(1)?"."

echo?'

';

var_dump($last);

var_dump($realLast);

var_dump($substr);

[#28]

Evan K [2008-02-28 13:03:15]

I?encountered?the?odd?situation?of?having?a?string?containing?unexpanded?escape?sequences?that?I?wanted?to?expand,?but?also?contained?dollar?signs?that?would?be?interpolated?as?variables.??"$5.25\n",?for?example,?where?I?want?to?convert?\n?to?a?newline,?but?don't?want?attempted?interpolation?of?$5.

Some?muddling?through?docs?and?many?obscenties?later,?I?produced?the?following,?which?expands?escape?sequences?in?an?existing?string?with?NO?interpolation.

returnpreg_replace_callback('/\\\([nrtvf]|[0-7]{1,3}|[0-9A-Fa-f]{1,2})?/',create_function('$matches','return?($matches[0]?==?"\\\\")???""?:?eval(?sprintf(\'return?"%s";\',?$matches[0])?);'),$string);

}//?a?string?to?test,?and?show?the?before?and?after$before='Quantity:\t500\nPrice:\t$5.25?each';$after=expand_escape($before);var_dump($before,$after);?>

[#29]

rkfranklin+php at gmail dot com [2007-09-26 12:35:45]

If?you?want?to?use?a?variable?in?an?array?index?within?a?double?quoted?string?you?have?to?realize?that?when?you?put?the?curly?braces?around?the?array,?everything?inside?the?curly?braces?gets?evaluated?as?if?it?were?outside?a?string.??Here?are?some?examples:

$i=0;$myArray[Person0]?=Bob;$myArray[Person1]?=George;//?prints?Bob?(the?++?is?used?to?emphasize?that?the?expression?inside?the?{}?is?really?being?evaluated.)echo"{$myArray['Person'.$i++]}
";//?these?print?Georgeecho"{$myArray['Person'.$i]}
";

echo"{$myArray["Person{$i}"]}
";//?These?don't?workecho"{$myArray['Person$i']}
";

echo"{$myArray['Person'$i]}
";//?These?both?throw?fatal?errors

//?echo?"$myArray[Person$i]
";

//echo?"$myArray[Person{$i}]
";?>

[#30]

Richard Neill [2007-05-31 20:31:30]

Unlike?bash,?we?can't?do

echo?"\a"???????#beep!

Of?course,?that?would?be?rather?meaningless?for?PHP/web,?but?it's?useful?for?PHP-CLI.?The?solution?is?simple:??echo?"\x07"

[#31]

og at gams dot at [2007-04-25 17:06:09]

easy?transparent?solution?for?using?constants?in?the?heredoc?format:

DEFINE('TEST','TEST?STRING');

$const?=?get_defined_constants();

echo?<<

{$const['TEST']}

END;

Result:

TEST?STRING

[#32]

penda ekoka [2007-04-24 10:14:28]

error?control?operator?(@)?with?heredoc?syntax:

the?error?control?operator?is?pretty?handy?for?supressing?minimal?errors?or?omissions.?For?example?an?email?form?that?request?some?basic?non?mandatory?information?to?your?users.?Some?may?complete?the?form,?other?may?not.?Lets?say?you?don't?want?to?tweak?PHP?for?error?levels?and?you?just?wish?to?create?some?basic?template?that?will?be?emailed?to?the?admin?with?the?user?information?submitted.?You?manage?to?collect?the?user?input?in?an?array?called?$form:

<?php //?creating?your?mailer$mailer=?newSomeMailerLib();$mailer->from='?System?';$mailer->to='admin@yourwebsite.com';$mailer->subject='New?user?request';//?you?put?the?error?control?operator?before?the?heredoc?operator?to?suppress?notices?and?warnings?about?unset?indices?like?this$mailer->body=?@<<

[#33]

bryant at zionprogramming dot com [2007-02-27 12:16:27]

As?of?(at?least)?PHP?5.2,?you?can?no?longer?convert?an?object?to?a?string?unless?it?has?a?__toString?method.?Converting?an?object?without?this?method?now?gives?the?error:

PHP?Catchable?fatal?error:??Object?of?class??could?not?be?converted?to?string?in??on?line?

Try?this?code?to?get?the?same?results?as?before:

}?else?{$string='Object';

}?>

[#34]

fmouse at fmp dot com [2007-02-21 10:20:46]

It?may?be?obvious?to?some,?but?it's?convenient?to?note?that?variables?_will_?be?expanded?inside?of?single?quotes?if?these?occur?inside?of?a?double-quoted?string.??This?can?be?handy?in?constructing?exec?calls?with?complex?data?to?be?passed?to?other?programs.??e.g.:

$foo?=?"green";

echo?"the?grass?is?$foo";

the?grass?is?green

echo?'the?grass?is?$foo';

the?grass?is?$foo

echo?"the?grass?is?'$foo'";

the?grass?is?'green'

[#35]

bishop [2006-03-28 12:58:56]

You?may?use?heredoc?syntax?to?comment?out?large?blocks?of?code,?as?follows:

echo?($test==?'foo'???'bar'?:?'baz');

echo?<<

This?is?text?you'll?never?see!

EOHTML;

function?defintion($params)?{

echo?'foo';

}

class?definition?extends?nothing?????{

function?definition($param)?{

echo?'do?nothing';

}

}

how?about?syntax?errors?;?=?gone,?I?bet._EOC;?>

Useful?for?debugging?when?C-style?just?won't?do.??Also?useful?if?you?wish?to?embed?Perl-like?Plain?Old?Documentation;?extraction?between?POD?markers?is?left?as?an?exercise?for?the?reader.

Note?there?is?a?performance?penalty?for?this?method,?as?PHP?must?still?parse?and?variable?substitute?the?string.

[#36]

webmaster at rephunter dot net [2005-11-30 08:57:07]

Use?caution?when?you?need?white?space?at?the?end?of?a?heredoc.?Not?only?is?the?mandatory?final?newline?before?the?terminating?symbol?stripped,?but?an?immediately?preceding?newline?or?space?character?is?also?stripped.

For?example,?in?the?following,?the?final?space?character?(indicated?by?\s?--?that?is,?the?"\s"?is?not?literally?in?the?text,?but?is?only?used?to?indicate?the?space?character)?is?stripped:

$string?=?<<

this?is?a?string?with?a?terminating?space\s

EOT;

In?the?following,?there?will?only?be?a?single?newline?at?the?end?of?the?string,?even?though?two?are?shown?in?the?text:

$string?=?<<

this?is?a?string?that?must?be

followed?by?a?single?newline

EOT;

[#37]

DELETETHIS dot php at dfackrell dot mailshell dot com [2005-11-01 08:05:59]

Just?some?quick?observations?on?variable?interpolation:

Because?PHP?looks?for?{??to?start?a?complex?variable?expression?in?a?double-quoted?string,?you?can?call?object?methods,?but?not?class?methods?or?unbound?functions.

This?works:

functionb()?{

return"World";

}

}$c=?newa;

echo"Hello{$c->b()}.\n"?>

While?this?does?not:

return"World";

}

echo"Hello?{b()}\n";?>

Also,?it?appears?that?you?can?almost?without?limitation?perform?other?processing?within?the?argument?list,?but?not?outside?it.??For?example:

$true=true;define("HW","Hello?World");

echo"{$true&&HW}";?>

gives:?Parse?error:?parse?error,?unexpected?T_BOOLEAN_AND,?expecting?'}'?in?-?on?line?3

There?may?still?be?some?way?to?kludge?the?syntax?to?allow?constants?and?unbound?function?calls?inside?a?double-quoted?string,?but?it?isn't?readily?apparent?to?me?at?the?moment,?and?I'm?not?sure?I'd?prefer?the?workaround?over?breaking?out?of?the?string?at?this?point.

[#38]

lelon at lelon dot net [2004-10-27 12:01:45]

You?can?use?the?complex?syntax?to?put?the?value?of?both?object?properties?AND?object?methods?inside?a?string.??For?example...

public$one=1;

public?functiontwo()?{

return2;

}

}$test=?newTest();

echo"foo{$test->one}bar{$test->two()}";?>

Will?output?"foo?1?bar?2".

However,?you?cannot?do?this?for?all?values?in?your?namespace.??Class?constants?and?static?properties/methods?will?not?work?because?the?complex?syntax?looks?for?the?'$'.

constONE=1;

}

echo"foo?{Test::ONE}?bar";?>

This?will?output?"foo?{Test::one}?bar".??Constants?and?static?properties?require?you?to?break?up?the?string.

[#39]

Jonathan Lozinski [2004-08-06 12:03:58]

A?note?on?the?heredoc?stuff.

If?you're?editing?with?VI/VIM?and?possible?other?syntax?highlighting?editors,?then?using?certain?words?is?the?way?forward.??if?you?use?<<

I?just?found?this?out?and?used?sed?to?alter?all?EOF?to?HTML.

JAVASCRIPT?also?works,?and?possibly?others.??The?only?thing?about?<<?tags..,??so?use?HTML?instead,?which?will?correctly?highlight?all?JavaScript?too..

You?can?also?use?EOHTML,?EOSQL,?and?EOJAVASCRIPT.

[#40]

www.feisar.de [2004-04-28 07:49:00]

watch?out?when?comparing?strings?that?are?numbers.?this?example:

$x1='111111111111111111';$x2='111111111111111112';

echo?($x1==$x2)??"true\n":"false\n";?>

will?output?"true",?although?the?strings?are?different.?With?large?integer-strings,?it?seems?that?PHP?compares?only?the?integer?values,?not?the?strings.?Even?strval()?will?not?work?here.

To?be?on?the?safe?side,?use:

$x1?===?$x2

[#41]

atnak at chejz dot com [2004-04-11 15:53:50]

Here?is?a?possible?gotcha?related?to?oddness?involved?with?accessing?strings?by?character?past?the?end?of?the?string:

$string?=?'a';

var_dump($string[2]);??//?string(0)?""

var_dump($string[7]);??//?string(0)?""

$string[7]?===?'';??//?TRUE

It?appears?that?anything?past?the?end?of?the?string?gives?an?empty?string..??However,?when?E_NOTICE?is?on,?the?above?examples?will?throw?the?message:

Notice:??Uninitialized?string?offset:??N?in?FILE?on?line?LINE

This?message?cannot?be?specifically?masked?with?@$string[7],?as?is?possible?when?$string?itself?is?unset.

isset($string[7]);??//?FALSE

$string[7]?===?NULL;??//?FALSE

Even?though?it?seems?like?a?not-NULL?value?of?type?string,?it?is?still?considered?unset.

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