php如何判断一个字所占的字节数。
win7里面好像又新增加了一些字。字节数是4位的。
如何判断出一个字符串中存在这种汉字。比如：
“abc我我@我”
@代表字节数位4的汉字。 当我挨个取字符的时候，就把@当成两个汉字来取了。
求高手赐教 如何判断初这个字的存在， 用JS也可以
------解决方案--------------------
GB 18030的双字节部分完全采用了GBK的内码系统。在此基础上，做了四字节扩展，四个字节的编码空间依次是：0x81到0xFE，0x30到0x39，0x81到0xFE，0x30到0x39。总共1,587,600个码位
就是说你不能仅仅判断一个字节，如果第二个字节的值是在0x30到0x39范围里时，他就是4字节的汉字了
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