Function 不給正常 output

Question

我正在嘗試編譯我的函數練習。 我嘗試了很多次編譯這個，但我遇到了這個問題。

下面是我的代碼：

#include <stdio.h>
int displayFlow();
int main(){
    int displayFlow();
   
}
int displayFlow(){

int try1,try2,try3;
printf("enter any given number...\n");
scanf("%d", &try1);
printf("if u entered above 10, ur out\n...please enter another guess...\n");
scanf("%d", &try2);
printf("if u entered below 5 then u won! !");


}

這是我得到的 output：

function.c:22:5: note: declared here
 int test(){

Answer 1

您在 main 中再次聲明了您的 function。 從 displayFlow 的前面刪除 int。

#include <stdio.h>
int displayFlow();
int main(){
    displayFlow();

}
int displayFlow(){

int try1,try2,try3;
printf("enter any given number...\n");
scanf("%d", &try1);
printf("if u entered above 10, ur out\n...please enter another guess...\n");
scanf("%d", &try2);
printf("if u entered below 5 then u won! !");


}

Answer 2

我又犯了一個錯誤：你把function的displayFlow定義為'int'類型，但是你意識到function時沒有寫'return'。

#include <stdio.h>
int displayFlow();
int main(){
    displayFlow(); //you just abandon the return value?

}
int displayFlow(){

int try1,try2,try3;
printf("enter any given number...\n");
scanf("%d", &try1);
printf("if u entered above 10, ur out\n...please enter another guess...\n");
scanf("%d", &try2);
printf("if u entered below 5 then u won! !");
//Here is something absent. What do you want to return ? or you just want to return nothing? if so, you should modify the function return value type to 'void',please.
//return ??;
}

Answer 3

方法main里面設置return就行了，因為他要return int

int main() {
return displayFlow();

}