包含字母的字符串 字母全部大写

-(NSString *)toUpper:(NSString *)str{
    for (NSInteger i=0; i<str.length; i++) {
        if ([str characterAtIndex:i]>='a'&[str characterAtIndex:i]<='z') {
            //A  65  a  97
            char  temp=[str characterAtIndex:i]-32;
            NSRange range=NSMakeRange(i, 1);
            str=[str stringByReplacingCharactersInRange:range withString:[NSString stringWithFormat:@"%c",temp]];
        }
    }
    return str;
}