为什么有错误C2100：非法间接 [英] why is there error C2100: illegal indirection

问题描述

#include <stdio.h>

//function declaration
void dispTariff(float);
float getTariff(int);

//declare and initialize data
int eusage[]={800,650,525,450,420,405,400,400,400,400};
#define tariff 25;
void main(void)
{
	float usageA,usageB,increase;
	usageA=getTariff(5);
	usageB=getTariff(8);
	increase=((usageB-usageA)/usageA*100);

	//print increase in percentage
	printf("increase in percentage is %2.2f%%\n",increase);

}//main
float getTariff(int duration)
{
	int j=0;
	float ebill=0;
	for(j=0,j<duration;j++;)>
	{
		ebill=ebill+tariff*(eusage[j]/1000.0);
	}
	printf("total bill after 6 hours %.2fcent\n",ebill);
	return ebill;
}

推荐答案

错误来源在这里：

The error source is here:

#define tariff 25;

预处理器将用 25替换<​​code>关税的出现; 以便编译器稍后看到这一行：

The preprocessor will replace the occurence of tariff with 25; so that the compiler later sees this line:

ebill=ebill+25;*(eusage[j]/1000.0);

分号定义表达式的结尾， *（eusage [j] /1000.0）被解释为间接运算符的另一个表达式（*）应用于非指针值。

因此将其更改为：

The semicolon defines the end of an expression and *(eusage[j]/1000.0) is interpreted as another expression where the indirection operator (*) is applied to a non-pointer value.
So change it to:

#define tariff 25

但是你的代码中还有另一个错误。线路

But there is also another error in your code. The line

for(j=0,j<duration;j++;)

应该是

should probably be

for(j=0;j<duration;j++)

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