PHP rare word processing method

In daily PHP programming, we will inevitably encounter some rare Chinese words. Although these words are not commonly used, they must be used in some specific situations. Let's discuss several ways in which PHP handles rare words.

1. Use Unicode encoding

Unicode is an international character set that can represent almost all characters, including rare Chinese characters. In PHP, to use Unicode encoding to process rare words, you generally need to use PHP's built-in functions chr() and ord().

1. chr() function

chr() function can convert a Unicode code into the corresponding character. Its syntax is as follows:

string chr( int $ascii)

Among them, $ascii is a decimal value of Unicode code.

For example, to output characters with Unicode code 23456, you can write:

echo chr(23456); // Output a rare Chinese character

2. ord () function

ord() function can convert a character into the corresponding Unicode code. Its syntax is as follows:

int ord(string $string)

Among them, $string is the character to be converted, which can be a Chinese character or a rare character.

For example, to output the Unicode code of rare Chinese characters, you can write like this:

echo ord("?"); // Output 23459

2. Use mbstring extension

mbstring is a built-in extension of PHP. It provides a series of functions for processing multi-byte characters, including rare Chinese characters. To use mbstring extension to process rare words, you generally need to use the following three functions:

1. mb_strlen() function

mb_strlen() function can return the number of characters in a string , including rare Chinese characters. The syntax is as follows:

int mb_strlen(string $string [, string $encoding = mb_internal_encoding()])

Among them, $string is the string to calculate the number of characters, and $encoding is the The encoding format of the string. If not specified, mb_internal_encoding() is used by default.

For example, to calculate how many characters, including rare Chinese characters, are contained in a string, you can write like this:

$str = "Rare Chinese characters?";
echo mb_strlen( $str); // Output 6

2. mb_substr() function

mb_substr() function can extract a substring of a string, including rare Chinese characters. The syntax is as follows:

string mb_substr(string $string, int $start [, int $length [, string $encoding = mb_internal_encoding()]])

Among them, $string is to be extracted The string of the substring, $start is the starting position of extraction, $length is the length of extraction, $encoding is the encoding format of the string, if not specified, mb_internal_encoding() is used by default.

For example, to extract a substring from a string, including rare Chinese characters, you can write like this:

$str = "Rare Chinese characters?";
echo mb_substr( $str, 2, 3); // Output "unusual"

3. mb_convert_encoding() function

mb_convert_encoding() function can convert a string from an encoding format Convert to another encoding format, including rare Chinese characters. The syntax is as follows:

string mb_convert_encoding(string $string, string $to_encoding [, mixed $from_encoding = mb_internal_encoding()])

Among them, $string is the string to be converted, $to_encoding is the target encoding format, $from_encoding is the original encoding format, if not specified, mb_internal_encoding() is used by default.

For example, to convert a string from UTF-8 encoding to GB2312 encoding, including rare Chinese characters, you can write like this:

$str = "Uncommon Chinese characters?";
echo mb_convert_encoding($str, "GB2312", "UTF-8");

3. Use iconv extension

iconv extension is a built-in extension of PHP, which provides a A series of functions are used to process character encoding conversion, including rare Chinese characters. To use the iconv extension to process rare characters, you generally need to use the following two functions:

1. iconv_strlen() function

iconv_strlen() function can return the number of characters in a string , including rare Chinese characters. The syntax is as follows:

int iconv_strlen(string $string [, string $charset = ini_get("iconv.internal_encoding")])

Among them, $string is the string to calculate the number of characters , $charset is the encoding format of the string. If not specified, ini_get("iconv.internal_encoding") is used by default.

For example, to calculate how many characters, including rare Chinese characters, are contained in a string, you can write like this:

$str = "Rare Chinese characters?";
echo iconv_strlen( $str); // Output 6

2. iconv_substr() function

iconv_substr() function can extract a substring of a string, including rare Chinese characters. The syntax is as follows:

string iconv_substr(string $string, int $start [, int $length [, string $charset = ini_get("iconv.internal_encoding")]])

Among them, $string is the string to extract the substring, $start is the starting position of extraction, $length is the length of extraction, $charset is the encoding format of the string, if not specified, ini_get("iconv.internal_encoding is used by default ").

For example, to extract a substring from a string, including rare Chinese characters, you can write like this:

$str = "Rare Chinese characters?";
echo iconv_substr( $str, 2, 3); // Output "uncommon"

Summary

The above are several methods for processing rare Chinese characters in PHP. The use of Unicode encoding relies on PHP's built-in functions, and the use of mbstring and iconv extensions provide more convenient processing tools. In actual programming, appropriate methods should be selected according to actual needs in order to better handle rare Chinese characters.

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