如：
while((numGuess!=numRand)&&(numGuess>=0)&& (numGuess !== exp[0-9] )){ //这里我想排除非法字符
     if(numGuess>numRand){
             System.out.println("你猜的数字太大了，请重新猜测！");
            numGuess=in.nextInt();
     }else if(numGuess<numRand){
           System.out.println("你猜的数字太小了，请重新猜测！");
           numGuess=in.nextInt();
      }else{
           System.out.println("你猜的不是数字，请重新猜测！");
           numGuess=in.nextInt();
   }
}