PHP全角和半角字符怎么去掉

要去掉字符串中的全角和半角字符，可以使用PHP中的一些字符串处理函数和正则表达式来实现。

1. 去掉全角字符：

全角字符是指在Unicode字符集中编码值大于等于65281（0xFF01）的字符。可以使用正则表达式来匹配并移除全角字符。

“`php
function removeFullWidthCharacters($str) {
return preg_replace(‘/[^\x00-\xff]/’, ”, $str);
}

$str = “Ｈｅｌｌｏ，Ｗｏｒｌｄ！”;
$result = removeFullWidthCharacters($str);
echo $result; // 输出 Hello, World!
“`

2. 去掉半角字符：

半角字符是指在Unicode字符集中编码值大于等于33（0x21）且小于等于126（0x7E）的字符。可以使用正则表达式来匹配并移除半角字符。

“`php
function removeHalfWidthCharacters($str) {
return preg_replace(‘/[\x21-\x7E]/’, ”, $str);
}

$str = “Hello, World!”;
$result = removeHalfWidthCharacters($str);
echo $result; // 输出 ，！
“`

3. 同时去掉全角和半角字符：

如果需要同时去掉全角和半角字符，可以结合上述的正则表达式来实现。

“`php
function removeFullAndHalfWidthCharacters($str) {
$str = preg_replace(‘/[^\x00-\xff]/’, ”, $str); // 去掉全角字符
$str = preg_replace(‘/[\x21-\x7E]/’, ”, $str); // 去掉半角字符
return $str;
}

$str = “Ｈｅｌｌｏ，Ｗｏｒｌｄ！Hello, World!”;
$result = removeFullAndHalfWidthCharacters($str);
echo $result; // 输出 Hello, World!
“`

以上是一种基本的方法来去掉字符串中的全角和半角字符。根据具体的需求，可以根据实际情况进行调整和修改。

要去掉PHP字符串中的全角和半角字符，我们可以使用正则表达式或者使用内置的字符串函数来实现。下面是几种方法：

1. 使用正则表达式去掉全角和半角字符：

“`php
$str = “ｐｈｐ全角和半角字符”;
$str = preg_replace(‘/[\x{FF01}-\x{FF5E}]/u’, ”, $str);
echo $str; // 输出：php全角和半角字符
“`

这里使用了 Unicode 范围 [\x{FF01}-\x{FF5E}] 匹配全角字符，并使用 preg_replace() 函数将其替换为空字符串。

2. 使用mb_convert_kana()函数去掉全角和半角字符：

“`php
$str = “ｐｈｐ全角和半角字符”;
$str = mb_convert_kana($str, “as”, “UTF-8”);
echo $str; // 输出：php全角和半角字符
“`

mb_convert_kana() 函数可以将字符串的全角字符转换为半角字符。

3. 使用自定义函数去掉全角和半角字符：

“`php
function remove_fullwidth_characters($str) {
$fullwidth_chars = array(
‘０’ => ‘0’, ‘１’ => ‘1’, ‘２’ => ‘2’, ‘３’ => ‘3’, ‘４’ => ‘4’, ‘５’ => ‘5’, ‘６’ => ‘6’,
‘７’ => ‘7’, ‘８’ => ‘8’, ‘９’ => ‘9’, ‘Ａ’ => ‘A’, ‘Ｂ’ => ‘B’, ‘Ｃ’ => ‘C’, ‘Ｄ’ => ‘D’,
‘Ｅ’ => ‘E’, ‘Ｆ’ => ‘F’, ‘Ｇ’ => ‘G’, ‘Ｈ’ => ‘H’, ‘Ｉ’ => ‘I’, ‘Ｊ’ => ‘J’, ‘Ｋ’ => ‘K’,
‘Ｌ’ => ‘L’, ‘Ｍ’ => ‘M’, ‘Ｎ’ => ‘N’, ‘Ｏ’ => ‘O’, ‘Ｐ’ => ‘P’, ‘Ｑ’ => ‘Q’, ‘Ｒ’ => ‘R’,
‘Ｓ’ => ‘S’, ‘Ｔ’ => ‘T’, ‘Ｕ’ => ‘U’, ‘Ｖ’ => ‘V’, ‘Ｗ’ => ‘W’, ‘Ｘ’ => ‘X’, ‘Ｙ’ => ‘Y’,
‘Ｚ’ => ‘Z’, ‘ａ’ => ‘a’, ‘ｂ’ => ‘b’, ‘ｃ’ => ‘c’, ‘ｄ’ => ‘d’, ‘ｅ’ => ‘e’, ‘ｆ’ => ‘f’,
‘ｇ’ => ‘g’, ‘ｈ’ => ‘h’, ‘ｉ’ => ‘i’, ‘ｊ’ => ‘j’, ‘ｋ’ => ‘k’, ‘ｌ’ => ‘l’, ‘ｍ’ => ‘m’,
‘ｎ’ => ‘n’, ‘ｏ’ => ‘o’, ‘ｐ’ => ‘p’, ‘ｑ’ => ‘q’, ‘ｒ’ => ‘r’, ‘ｓ’ => ‘s’, ‘ｔ’ => ‘t’,
‘ｕ’ => ‘u’, ‘ｖ’ => ‘v’, ‘ｗ’ => ‘w’, ‘ｘ’ => ‘x’, ‘ｙ’ => ‘y’, ‘ｚ’ => ‘z’,
‘　’ => ‘ ‘, ‘！’ => ‘!’, ‘＂’ => ‘”‘, ‘＃’ => ‘#’, ‘＄’ => ‘$’, ‘％’ => ‘%’, ‘＆’ => ‘&’,
‘＇’ => “‘”, ‘（’ => ‘(‘, ‘）’ => ‘)’, ‘＊’ => ‘*’, ‘＋’ => ‘+’, ‘，’ => ‘,’, ‘－’ => ‘-‘,
‘．’ => ‘.’, ‘／’ => ‘/’, ‘：’ => ‘:’, ‘；’ => ‘;’, ‘＜’ => ‘<', '＝' => ‘=’, ‘＞’ => ‘>’,
‘？’ => ‘?’, ‘＠’ => ‘@’, ‘［’ => ‘[‘, ‘＼’ => ‘\\’, ‘］’ => ‘]’, ‘＾’ => ‘^’, ‘＿’ => ‘_’,
‘｀’ => ‘`’, ‘｛’ => ‘{‘, ‘｜’ => ‘|’, ‘｝’ => ‘}’, ‘～’ => ‘~’
);
return strtr($str, $fullwidth_chars);
}

$str = “ｐｈｐ全角和半角字符”;
$str = remove_fullwidth_characters($str);
echo $str; // 输出：php全角和半角字符
“`

这个自定义函数使用了一个映射表，将全角字符替换为对应的半角字符。

4. 使用str_replace()函数去掉全角和半角字符：

“`php
function remove_fullwidth_characters($str) {
$search = array(‘０’, ‘１’, ‘２’, ‘３’, ‘４’, ‘５’, ‘６’, ‘７’, ‘８’, ‘９’,
‘Ａ’, ‘Ｂ’, ‘Ｃ’, ‘Ｄ’, ‘Ｅ’, ‘Ｆ’, ‘Ｇ’, ‘Ｈ’, ‘Ｉ’, ‘Ｊ’, ‘Ｋ’, ‘Ｌ’, ‘Ｍ’, ‘Ｎ’, ‘Ｏ’, ‘Ｐ’, ‘Ｑ’, ‘Ｒ’, ‘Ｓ’, ‘Ｔ’, ‘Ｕ’, ‘Ｖ’, ‘Ｗ’, ‘Ｘ’, ‘Ｙ’, ‘Ｚ’,
‘ａ’, ‘ｂ’, ‘ｃ’, ‘ｄ’, ‘ｅ’, ‘ｆ’, ‘ｇ’, ‘ｈ’, ‘ｉ’, ‘ｊ’, ‘ｋ’, ‘ｌ’, ‘ｍ’, ‘ｎ’, ‘ｏ’, ‘ｐ’, ‘ｑ’, ‘ｒ’, ‘ｓ’, ‘ｔ’, ‘ｕ’, ‘ｖ’, ‘ｗ’, ‘ｘ’, ‘ｙ’, ‘ｚ’,
‘　’, ‘！’, ‘＂’, ‘＃’, ‘＄’, ‘％’, ‘＆’, ‘＇’, ‘（’, ‘）’, ‘＊’, ‘＋’, ‘，’, ‘－’, ‘．’, ‘／’, ‘：’, ‘；’, ‘＜’, ‘＝’, ‘＞’, ‘？’, ‘＠’, ‘［’, ‘＼’, ‘］’, ‘＾’, ‘＿’, ‘｀’, ‘｛’, ‘｜’, ‘｝’, ‘～’
);
$replace = array(‘0’, ‘1’, ‘2’, ‘3’, ‘4’, ‘5’, ‘6’, ‘7’, ‘8’, ‘9’,
‘A’, ‘B’, ‘C’, ‘D’, ‘E’, ‘F’, ‘G’, ‘H’, ‘I’, ‘J’, ‘K’, ‘L’, ‘M’, ‘N’, ‘O’, ‘P’, ‘Q’, ‘R’, ‘S’, ‘T’, ‘U’, ‘V’, ‘W’, ‘X’, ‘Y’, ‘Z’,
‘a’, ‘b’, ‘c’, ‘d’, ‘e’, ‘f’, ‘g’, ‘h’, ‘i’, ‘j’, ‘k’, ‘l’, ‘m’, ‘n’, ‘o’, ‘p’, ‘q’, ‘r’, ‘s’, ‘t’, ‘u’, ‘v’, ‘w’, ‘x’, ‘y’, ‘z’,
‘ ‘, ‘!’, ‘”‘, ‘#’, ‘$’, ‘%’, ‘&’, “‘”, ‘(‘, ‘)’, ‘*’, ‘+’, ‘,’, ‘-‘, ‘.’, ‘/’, ‘:’, ‘;’, ‘<', '=', '>‘, ‘?’, ‘@’, ‘[‘, ‘\\’, ‘]’, ‘^’, ‘_’, ‘`’, ‘{‘, ‘|’, ‘}’, ‘~’
);
return str_replace($search, $replace, $str);
}

$str = “ｐｈｐ全角和半角字符”;
$str = remove_fullwidth_characters($str);
echo $str; // 输出：php全角和半角字符
“`

这个函数使用了str_replace()函数将全角字符替换为对应的半角字符。

以上是四种去掉PHP字符串中的全角和半角字符的方法。根据实际需求选择合适的方法来处理字符串。

要去掉PHP中的全角和半角字符，可以通过以下几种方法和操作流程来实现。

一、使用PHP的内置函数处理字符

1. 使用mb_convert_kana函数

mb_convert_kana是一个多字节字符处理函数，可以将全角字符转换为半角字符，也可以将半角字符转换为全角字符。通过指定参数’K’可以将全角字符转换为半角字符，指定参数’n’可以将半角字符转换为全角字符。具体操作如下：

“`php
$str = ‘ＡＢＣ１２３ａｂｃ’; // 含有全角字符和半角字符的字符串

// 将全角字符转换为半角字符
$halfwidthStr = mb_convert_kana($str, ‘K’, ‘UTF-8’);

// 将半角字符转换为全角字符
$fullwidthStr = mb_convert_kana($str, ‘n’, ‘UTF-8’);
“`

2. 使用preg_replace函数

preg_replace是一个正则表达式替换函数，可以使用正则表达式匹配并替换字符串中的字符。通过使用正则表达式来匹配全角或半角字符，然后进行替换即可。具体操作如下：

“`php
$str = ‘ＡＢＣ１２３ａｂｃ’; // 含有全角字符和半角字符的字符串

// 替换全角字符为半角字符
$halfwidthStr = preg_replace(‘/[\x{FF01}-\x{FF5E}]/u’, ”, $str);

// 替换半角字符为全角字符
$fullwidthStr = preg_replace(‘/[\x{0021}-\x{007E}]/u’, ”, $str);
“`

二、使用正则表达式去掉字符

1. 去掉全角字符

如果只需要去掉全角字符，可以使用正则表达式匹配全角字符，并将其替换为空字符串。具体操作如下：

“`php
$str = ‘ＡＢＣ１２３ａｂｃ’; // 含有全角字符和半角字符的字符串

// 去掉全角字符
$halfwidthStr = preg_replace(‘/[\x{FF01}-\x{FF5E}]/u’, ”, $str);
“`

2. 去掉半角字符

如果只需要去掉半角字符，可以使用正则表达式匹配半角字符，并将其替换为空字符串。具体操作如下：

“`php
$str = ‘ＡＢＣ１２３ａｂｃ’; // 含有全角字符和半角字符的字符串

// 去掉半角字符
$fullwidthStr = preg_replace(‘/[\x{0021}-\x{007E}]/u’, ”, $str);
“`

三、使用strtr函数去掉字符

1. 去掉全角字符

可以使用strtr函数将字符串中的全角字符替换为空字符串。具体操作如下：

“`php
$str = ‘ＡＢＣ１２３ａｂｃ’; // 含有全角字符和半角字符的字符串

// 去掉全角字符
$halfwidthStr = strtr($str, [
‘！’ => ”,
‘＂’ => ”,
// … 其他全角字符依此类推
]);
“`

2. 去掉半角字符

可以使用strtr函数将字符串中的半角字符替换为空字符串。具体操作如下：

“`php
$str = ‘ＡＢＣ１２３ａｂｃ’; // 含有全角字符和半角字符的字符串

// 去掉半角字符
$fullwidthStr = strtr($str, [
‘!’ => ”,
‘”‘ => ”,
// … 其他半角字符依此类推
]);
“`

以上就是去掉PHP中全角和半角字符的一些方法和操作流程，可以根据实际需求选择适合的方法来处理字符。