private double parseMulOrDiv() throws Exception{
		char op;	//
		double result;	//
		double partialResult;	//ӱʽĽ
		
		//ָ㵱ǰӱʽֵ
		result=this.parseExponent();
		//ǰǵĵһĸǳ˳ȡģг˳
		while((op=this.token.charAt(0))=='*'||op=='/'||op=='%'){
			this.getToken();//ȡһ
			//ָ㵱ǰӱʽֵ
			partialResult=this.parseExponent();
			switch(op){
			case '*':
				//ǳ˷ѴʽֵԵǰӱʽֵ
				result=result*partialResult;
				break;
			case '/':
				//ǳжϵǰӱʽֵǷΪ00׳0쳣
				if(partialResult==0.0){
					this.handleError(DIVBYZERO_ERROR);
				}
				//Ϊ0г
				result=result/partialResult;
				break;
			case '%':
				//ȡģ㣬ҲҪжϵǰӱʽֵǷΪ0
				//Ϊ0׳쳣
				if(partialResult==0.0){
					this.handleError(DIVBYZERO_ERROR);
				}
				//ȡģ
				result=result%partialResult;
				break;
			}
		}
		return result;
	}