“一元*”的无效类型参数（有“int”）

Question

我很抱歉重复这个问题，但我无法理解（我认为我的问题是什么）指针。有人可以为我解释一下吗？我已经浏览了一堆 stackoverflow 问题、c 教程和它最令人困惑的问题，因为每个解决方案似乎都相互矛盾 - 如果我看到我的代码被修复，我相信这将有助于我完全理解

1 #include <stdio.h>
2 getinput()
3 {
4 int *employeeSalary[5];
5 int i;
6         for(i=0;i<5;i++)
7         {
8                 printf("Enter details of employee no. %d :",i+1);
9                 scanf("%d",&employeeSalary[i]);
10         }
11 return(*employeeSalary);
12 }
13 
14 int payrise(int *employeeSalary[])
15 {
16 int *newSalary = ((employeeSalary*0.20)*100);
17 return(*newSalary);
18 }
19 
20 int highestSalary(int *newSalary)
21 {
22 int i = 0;
23 int biggestSalary;
24 int element;
25         if(newSalary[i] >= newSalary[i])
26         {
27                 biggestSalary = newSalary[i];
28                 element = i;
29         }
30 return(biggestSalary, element);
31 }
32 
33 void display(int *employeeSalary, int *newSalary, int biggestSalary, int element)
34 {
35 printf("The old salary was %d and the new one is %d ", employeeSalary, newSalary);
36 printf("The biggest salaray is %d in element %d", biggestSalary, element);
37 }
38 
39 
40 int main()
41 {
42 int initialSalary = getinput();
43 int payIncrease = payrise(initialSalary);
44 int largestSalary = highestSalary(payIncrease);
45 display(initialSalary, payIncrease, largestSalary);
46 return(0);
47 }

这些是我遇到的错误

11: error: invalid type argument of ‘unary *’ (have ‘int’)
16: error: invalid operands to binary * (have ‘int ***’ and ‘double’) 
17: error: invalid type argument of ‘unary *’ (have ‘int’)
45: error: too few arguments to function ‘display’

Answer 1

在第 2 行，您有一个看起来像没有返回类型的函数声明，请尝试添加一个。

Answer 2

主要是打字问题 @lijat 说的是正确的。在第 16 行，你有一个没有不同类型转换的作业。 ((employeeSalary*0.20)*100) 是 int [] 类型，实际上是 int* 所以你要么需要左侧 int** 要么再取消引用右侧（在开头添加 *表达方式。 第 17 行返回后需要一个空格。 第 45 行你缺少一个参数，函数 display 收到 4 而你只给了它 3。

Answer 3

您使用的指针都错了。请在尝试使用指针之前阅读指针。我会尽量指出你的错误：

2 getinput() //<-- no return type? should return int*
3 {
4 int *employeeSalary[5];
5 int i;
6         for(i=0;i<5;i++)
7         {
8                 printf("Enter details of employee no. %d :",i+1);
9                 scanf("%d",&employeeSalary[i]);
10         }
11 return(*employeeSalary); //<-- I guess you wanted to return the whole array. This only returns the 1st element
12 }




14 int payrise(int *employeeSalary[])//<-- must return an integer
15 {
16 int *newSalary = ((employeeSalary*0.20)*100); <-- employeeSalary is an array of int pointers, therefore this is invalid
17 return(*newSalary); 
18 }




20 int highestSalary(int *newSalary) //<-- must return an integer like 5 or 3 ...
21 {
22 int i = 0;
23 int biggestSalary;
24 int element;
25         if(newSalary[i] >= newSalary[i]) //<-- isn't this always true, i.e. always equal?
26         {
27                 biggestSalary = newSalary[i];
28                 element = i;
29         }
30 return(biggestSalary, element); //<-- no comment! I don't know what you are trying to do here
31 }


void display(int *employeeSalary, int *newSalary, int biggestSalary, int element)
34 {
35 printf("The old salary was %d and the new one is %d ", employeeSalary, newSalary);//employeeSlary and newSalary are pointersn you need to dereference them.
36 printf("The biggest salaray is %d in element %d", biggestSalary, element);
37 }

我强烈建议您在线查找 c 教程并按照它进行操作。您似乎无法区分变量类型和指针。

Answer 4

#include <stdio.h>
#include <stdlib.h>

#define NUM_OF_EMPLOYEE 5

int *getinput(void){
    int i, *employeeSalary = calloc(NUM_OF_EMPLOYEE, sizeof(int));
    for(i=0;i<NUM_OF_EMPLOYEE;++i){
        printf("Enter details of employee no. %d :", i+1);
        scanf("%d", &employeeSalary[i]);
    }
    return employeeSalary;
}

int *payrise(int employeeSalary[]){
    int i, *newSalary = malloc(NUM_OF_EMPLOYEE * sizeof(int));
    for(i=0;i<NUM_OF_EMPLOYEE;++i){
        newSalary[i] = employeeSalary[i]*1.20;//*0.20*100 = *20.0
    }
    return newSalary;
}

int highestSalary(int *newSalary){
    int biggestSalary = newSalary[0];
    int element = 0;
    int i = 0;

    for(i=1;i<NUM_OF_EMPLOYEE;++i){
        if(newSalary[i] > biggestSalary){
            biggestSalary = newSalary[i];
            element = i;
        }
    }
    return element;
}

void display(int *employeeSalary, int *newSalary, int biggestSalary, int element){
    int i;
    for(i=0;i<NUM_OF_EMPLOYEE;++i){
        printf("The old salary was %d and the new one is %d\n", employeeSalary[i], newSalary[i]);
    }
    printf("The biggest salaray is %d in element %d\n", biggestSalary, element);
}

int main(){
    int *initialSalary = getinput();
    int *payIncrease = payrise(initialSalary);
    int index = highestSalary(payIncrease);
    int largestSalary = payIncrease[index];
    display(initialSalary, payIncrease, largestSalary, index);

    free(initialSalary);free(payIncrease);
    return 0;
}