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This article will explain in detail the differences between htmlentities and htmlspecialchars, and the content of the article is of high quality, so the editor will share it for you as a reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

Many people think that htmlentities and htmlspecialchars have the same function, both format html code, I used to think so, but today I find that this is not the case.

The difference between htmlentities and htmlspecialchars

The code is as follows:

'& (ampersand) becomes' &'

'' (double quote) becomes' when ENT_NOQUOTES is not set.

'' (single quote) becomes' only when ENT_QUOTES is set.

''

Htmlspecialchars only converts the above html code, while htmlentities converts all the html code, along with the Chinese characters it cannot recognize.

We can compare with a simple example:

The code is as follows:

$str=' Test Page'

Echo htmlentities ($str)

/ / ², please do not have any information.

$str=' Test Page'

Echo htmlspecialchars ($str)

/ / Test page

The conclusion is that when there is Chinese, it is best to use htmlspecialchars, otherwise the code may be garbled.

Also refer to this custom function

The code is as follows:

Function my_excerpt ($html, $len) {

/ / $html should contain an HTML document.

/ / the HTML tag and javascript code will be removed in this example

/ / and white space characters. It will also put some general-purpose ones

/ / HTML entities are converted to the corresponding text.

$search = array ("'] *? >. *?'si", / / remove javascript

"'si", / / remove the HTML tag

"'([\ r\ n]) [\ s] +'", / / remove the white space character

"'& (quot | # 34);'I", / / replace HTML entity

"'& (amp | # 38);'I"

"'& (lt | # 60);'I"

"'& (gt | # 62);'I"

"'& (nbsp | # 160);'I"

"'& (iexcl | # 161);'I"

"'& (cent | # 162);'I"

"'& (pound | # 163);'I"

"'& (copy | # 169);'I"

"'& # (\ d+);'e"); / / run as PHP code

$replace = array (""

"

"\ 1"

"\"

"&"

"

"

Chr (161l)

Chr (162)

Chr (163)

Chr 169,

"chr (\\ 1)")

$text = preg_replace ($search, $replace, $html)

$text = trim ($text)

Return mb_strlen ($text) > = $len? Mb_substr ($text, 0, $len):''

}

The htmlspecialchar () function and the htmlentities () function are similar to the html code conversion, while htmlspecialchars_decode converts the code of the converted html into a conversion back.

We can compare with a simple example:

The code is as follows:

$str=' Test'

$transstr = htmlspecialchars ($str)

Echo $transstr. "

"

Echo htmlspecialchars_decode ($transstr) "

Run the above code and you can see the difference between the two.

It has always been known that the htmlentities and htmlspecialchars functions in PHP can convert special characters in html into the corresponding character entity (I don't know how to translate them), and I have always known that there is a difference between htmlentities and htmlspecialchars functions, but they have never been used, so I haven't studied the difference.

When I used it today, I didn't bother to look at the bird language in the PHP manual, thinking that this kind of question should have been written in Chinese, so the Google keyword "htmlentities htmlspecialchars", the answer is the same. I am so used to copying and pasting that even primary school students can do it. By comparison, it is found that each article probably consists of two parts:

The first part is to quote the instructions of the PHP manual:

The PHP manual says to htmlspecialchars:

The translations performed are:

The code is as follows:

'& (ampersand) becomes' &'

'' (double quote) becomes' when ENT_NOQUOTES is not set.

"'(single quote) becomes''only when ENT_QUOTES is set.

'To

The conclusion is that when there is Chinese, it is best to use htmlspecialchars, otherwise the code may be garbled.

Does the htmlentities function have only one argument? Of course not! htmlentities also has three optional parameters, $quote_style, $charset, and $double_encode, which are described in the manual as follows:

Defines character set used in conversion. The default character set is ISO-8859-1.

Judging from the output of the above program, $str is GB2312-encoded, and the hexadecimal value corresponding to the words "test page" is:

B2 E2 CA D4 D2 B3 C3 E6

However, it is parsed as an ISO-8859-1 code:

²/ m / m / s / s

It corresponds to the following in HTML character entity:

²/ m / m / s / s

Of course, it will be escaped by htmlentities, but as long as the correct coding is added as a parameter, the so-called Chinese garbled problem will not occur at all:

$str=' Test Page'

Echo htmlentities ($str, ENT_COMPAT, 'gb2312')

/ / the three people on the test page become a tiger and make a mistake.

Conclusion: the difference between htmlentities and htmlspecialchars is that htmlentities converts all html character entity, while htmlspecialchars converts only a few html character entity listed in the manual (that is, the basic characters that affect html parsing). In general, using htmlspecialchars to convert out basic characters is sufficient, and there is no need to use htmlentities. When you really want to use htmlentities, be careful to pass the correct encoding for the third parameter.

What is the difference between htmlentities and htmlspecialchars to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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