PHP 中将全角字符转换成半角的方法

摘要: 在许多收集用户信息的表单里，期望用户输入的是半角字符，但是无论你如何强调，如何提醒，还是会有粗心的用户提交全角数据，其实，在一些新手眼中，全角和半角根本就没有区别，甚至他们会觉得：我提交的明明是正确的信息，为什么会提示错误呢？
实际上，全角和半角有一一对应关系，而大多数用户并非故意输入错误的信息，所以，我们可以通过程序来避免这种情况的发生，最多，可以在转换后给用户一个确认的机会，这样，或许能够给用户一个更好的体验。 全半角英文数字的替换函数
//全角替换到半角
function SBC_DBC($Str) {
$Queue = 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 preg_replace("/([\xA3][\xB0-\xB9\xC1-\xDA\xE1-\xFA])/e", "\$Queue[\\1]", $Str);
}
//半角替换到全角
function DBC_SBC($Str) {
$Queue = 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 preg_replace("/([0-9a-zA-Z])/e", "\$Queue[\\1]", $Str);
}
///判断字符传中是否包含全角英文或者数字
$p = "/([\xA3][\xB0-\xB9\xC1-\xDA\xE1-\xFA])/e";
if(preg_match($p,$str)){
echo "yes";
}else{
echo "no";
}