I have code like this:
<?php
echo '<script type="text/javascript">';
echo 'var out="'.$txt.'";';
echo '</script>';
?>
Where $txt is a PHP variable that can contain newlines like this:
line1
line2 hello world
Which would end up like this:
var out="line1
line2 hello world";
Which will cause a Javascript error, of course.
What is the best way to handle this? The out variable will be used in a HTML textarea, so I don't think it can be parsed into <br>
$txt = str_replace( array( "\n", "\r" ), array( "\\n", "\\r" ), $txt );
should replace newlines. Don't do it this way.
This is a naïve implementation of string escaping for JavaScript. As you're actually trying to format a string for use in JavaScript, a much better solution would be to use json_encode:
$txt = json_encode($txt);
echo "<script>var out={$txt};</script>";
json_encode will correctly escape special characters in strings, such as quotes, tabs, form feeds, and other special unicode characters. It will also perform all the correct escaping for converting objects, arrays, numbers, and booleans.
you can add a \ at the end of a line to create a multi line String
var out="line1 \
line2 hello world";
Most of these don't work for me.
Normally, I'd use json_encode like
<?php
$MyVar = json_encode($MyVar);
?>
<javascript language='javascript'>
MyVar = <?php echo $MyVar; ?>
But for a quick fix you can just break a line like this:
Pay attention to the double quotes.
<?php
$MyVar = "line one here
then line two here
finally line five here";
//** OR
$MyVar = $MyVarA .
"
"
. $MyVarB;
?>
<HTML>
<HEAD>
<javascript language='javascript'>
Myvar = "<?php echo $MyVar; ?>";
. . .
You can use str_replace to convert line breaks into a different character (in this case, perhaps a space, but it depends how you want the output to show up)
$out = str_replace("\n", '\n', $in);
$content = str_replace( "\\n", "\\\\\\n", $content );
Result:
var a = "Hello \
World"
I tried this and it worked well.
<?php
echo '<script type="text/javascript">';
$txt = "line1 \\n line2 hello world";
echo 'var out="'.$txt.'";';
echo '</script>';
?>
I am using PHP 5.3
Related
<?php echo nl2br($valueu->getarea($rows['province'].'|'.$rows['city'].'|'.$rows['area'],' ')); ?></td>
how to put a line break in between city and area when outputted to a browser.
Thanks
Use \n. Just add it with the sting like this I."\n" like pie.
You can also use nl2br like this echo nl2br("One line.\nAnother line.");
Try double quote "\n".
If you use single quote '\n', PHP will just interpret as a literal \n, but within double quote, it will parse it as an escape sequence (newline character) and echo it. More about strings here.
echo nl2br('Hello \n world');
// -> Hello \n world
echo nl2br("Hello \n world");
// -> Hello <br /> world
In a browser, you may need to use "<br/>" instead of a newline "\n".
echo($valueu->getarea($rows['province'].'|'.$rows['city'].'<br />'.$rows['area'],' '));
Something like that?
I am running some ajax that sends escaped text from the client to a php page running on the server. The text has some carriage returns in it. When I echo these out using php they show up in the text as \n.
However when I try to replace \n using str_replace, the function does not find them.
This has been driving me crazy.
By contrast, I manually created a variable in the same php file with a bunch of \n s in it and in that case the same str_replace code replaced them fine.
Could there be some invisible characters or something throwing it off?
Thanks for any suggestions.
Following replace (all in PHP) works fine
$var = "some text\nsomemore text\nsome more text\nsome more";
echo $var; //displays above text
$strComma = str_replace("\n",",",$var);
echo "strComma".$strComma; \\all of the \n instances are replaced by comma
Following replace does not work
javascript (abbreviated)
var text = document.getElementById(textbox).value; //grabs text from client html
var text2 = escape(text); //escape needed to handle special characters in text
//send to php page
xmlhttp.open("GET","storetext.php?text="+text2,true);
xmlhttp.send();
PHP
$var = $_REQUEST['text'];
echo $var; //displays \n as above. So far so good.
$strComma = str_replace("\n",",",$var);
echo "strComma".$strComma; \\ replacement does not take place
This should work:
$strComma = str_replace("\\n",",",$var);
Two backslashes and then the n character. Like escaping the escape sequence.
When I try with str_replace nothing changes, but using preg_replace it does like this
$strComma = preg_replace("/\n/",",",$var);
ok, html
<html>
<head>
<script src="../../js/jquery_1_8_min.js" type="text/javascript"></script>
</head>
<body>
<script>
text = "some text\nsomemore text\nsome more text\nsome more";
text2 = escape(text)
$.post('lixo.php?'+Math.random(),{text:text2}, function(data) {
alert(data);
});
</script>
</body>
</html>
php
<?php
$var = $_POST["text"];
echo $var; //displays above text
$strComma = preg_replace("/%0A/",",",$var);
$strComma = preg_replace("/%20/",",",$var);
echo "<br>strComma = ".$strComma;
?>
when you escape your text \n becames %0A and white space becames %20
better php
<?php
$var = $_POST["text"];
echo $var."<br>";
$patterns = array();
$patterns[0] = "/%0A/";
$patterns[1] = "/%20/";
$replacements = array();
$replacements[0] = ",";
$replacements[1] = " ";
$strComma = preg_replace($patterns, $replacements,$var);
echo "<br>strComma = ".$strComma;
?>
I am trying to work on a script but I am stuck in one place.
Eg. To get a php output I have used..
str_php = """
<?php
echo "Hello World!";
?>"""
php_file = open("index.php", "w")
php_file.write(str_php)
php_file.close()
Ok, so I get the output as it is....
<?php
echo "Hello World!";
?>
So my php code is running. all good till here. But, the problem starts from when I try using "\" and "\n" and "\r"
str_php = """
<?php
echo "Hello World!"; \n echo "How are you"; \n echo "God bless you";
?>"""
php_file = open("index.php", "w")
php_file.write(str_php)
php_file.close()
But here I dont get the output as it is.
<?php
echo "Hello World!";
echo "How are you";
echo "God bless you";
?>
And the "\" it just vanishes... at an output.
Eg. I want an output of a php hyperlink something like...
str_php = """<?php
print("$dirArray[$index]");
?>"""
php_file = open("index.php", "w")
php_file.write(str_php)
php_file.close()
and the output I get is...
<?php
print("$dirArray[$index]");
?>
The "\" is missing and the php does not run creating error.
print("$dirArray[$index]") - Original
print("$dirArray[$index]") - python output
Can any one help me out with "\", "\n", "\r" ??
Just use "\" to escape the "\" character.
Since it is common to want to have long strings containing several "\", Python also allows one
to prefix the string opening quotes if ar r (for "raw") - inside such
a string, no escaping of "\n" to chr(10) or "\t" to chr(9) happens:
>>> print (r"Hello \n world!")
Hello \n world!
You need to escape your "\" with another backslash writting it as "\\".
If you use "\n" it will be parsed and make a newline. Try to use '\n', strings enclosed in '\n' are not parsed and it should print out as you want it to.
I have Learnt that Quotes doesn't matter in PHP.
But in the following code, if I try to use single quotes in eval(); I get error, on the other hand code works fine with Double Quotes.
$a = '2';
$b = '3';
$c = '$a+$b';
echo $c.'<br/>';
eval("\$c = \"$c\";");
//eval('\$c = \'$c\';'); //Parse error: syntax error, unexpected T_VARIABLE, expecting T_STRING
echo $c;
PHP.net says that escape sequences are not expanded when using single quotes.
Quotes do matter ;-)
<?php
$color = "red";
echo "My car is $color"; // Outputs "My car is red"
echo 'My car is $color'; // Outputs "My car is $color"
?>
Unlike double quotes, PHP does not parse variables in single quotes.
Example:
$name = 'John';
echo 'hello $name'; // hello $name
echo "hello $name"; // hello John
More Information
FYI, it isn't good idea to use eval in production environment for security reasons.
Using eval is a bad idea but if you are doing this for learning purpose then the correct way is
eval("\$c = \$c;");
.
don't use eval and update your string-quoting skills here:
The following example was lifted from: The PHP Manual
<?php
echo 'this is a simple string';
echo 'You can also have embedded newlines in
strings this way as it is
okay to do';
// Outputs: Arnold once said: "I'll be back"
echo 'Arnold once said: "I\'ll be back"';
// Outputs: You deleted C:\*.*?
echo 'You deleted C:\\*.*?';
// Outputs: You deleted C:\*.*?
echo 'You deleted C:\*.*?';
// Outputs: This will not expand: \n a newline
echo 'This will not expand: \n a newline';
// Outputs: Variables do not $expand $either
echo 'Variables do not $expand $either';
?>
I'm trying to get it once again.
I got a JS var which looks like this:
var test;
Now I write some JS with PHP:
<?php
$phpvar = "a text with
a linebreak";
echo "<script type='text/javascript'>
var test;
test = '" . $phpvar . "';
</script>";
?>
Now, if I run it, it outputs the source as follows:
<script type='text/javascript'>
var test;
test = 'a text with
a linebreak';
</script>
This gives me a JS exception:
ERROR: unterminated string literal
Somehow, JS seems not to recognize that there is a string on more than one line.
How can I realize this if, in the end, the string must have its linebreak again? (So, if all execution finishes, I must have the string including all linebreaks)
Thank you for your help ;)
Try this, if you use a \ at the end of a Javascript line, you can use multiple lines within a string.
<?php
$phpvar = "a text with
a linebreak";
echo "<script type='text/javascript'>
var test;
test = '" . str_replace("\n", "\\\n",$phpvar) . "';
</script>";
?>
escaping in php:
js: php:
<linebreak> \n
\ \\
\n \\n
If you want this:
var test = "te\
st";
console.log(test) > "test"
in this case you need to use a \ and <linebreak> (in js), so you need to replace the \n to \\ plus \n (in php)
<?php
$phpvar = "a text with
a linebreak";
echo "<script type='text/javascript'>
var test;
test = '" . str_replace("\n", "\\\n",$phpvar) . "';
</script>";
?>
this keep the linebreaks as a php but not in the javasccript
But if you want to keep the linebreaks in javascript like this:
console.log(test) > "te
st"
You need to add a \n as an escaped string, not as a linebreak character.
So the code will look like this
var test = "te\n\
st"
console.log(test) > "te
st"
In this case you need a \n and a \ and a <linebeak> (in js), so you need to replace the the \n to a \\n plus \\ plus \n
<?php
$phpvar = "a text with
a linebreak";
echo "<script type='text/javascript'>
var test;
test = '" . str_replace("\n", "\\n\\\n",$phpvar) . "';
</script>";
?>
this keeps the linebreaks in php, and also add linebreaks into the javascript