suppose OneLineText is a string
Don't forget to check the index or it could be out of range! Lenthg checking must performe at first rather than access the char in the string or the string will be also out of range!
（本文来源于图老师网站，更多请访问http://m.tulaoshi.com/bianchengyuyan/）The following will be out of range because it may acces the character out of the rang before it check the boundary.
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while( isalpha( OneLineText.at( i ) ) && ( i LengthOfText ) )
{
i++ ;
}//end while
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The following code will be all right.
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while( ( i LengthOfText ) && isalpha( OneLineText.at( i ) ) )
{
i++ ;
}//end while
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