How to get the value that is returned from a function without running the function again?

For example:

int difficulty() {
    char x;
    while (true) {
        if (kbhit()) {
            x = getch();
            if (x == '1' || x == '2' || x == '3') {
                return x;
                break;
            }
        }
    }
    cout << "done";
}

This function is called in:

void Move(){
    if (HeadY >= Height-1 || HeadY <= 0 || HeadX >= Widht-1 || HeadX <= 0)
        Lose = false;
    char level=diffculty(); //**********
    if(level=='2' || level=='3'){
        for(int i=0;i<Ta_N;i  )
            if(HeadX==Ta_X[i] && HeadY==Ta_Y[i])
                Lose = false;
    }
}

And called in the menu function:

void menu(){
    if(kbhit()){
        x=getch();
        if(x=='s' || x=='S'){
            system("cls");
            table();
            while(Lose){
                Line();
                Input();
                Move(); //***********
                Sleep(50);
            }
            system("pause");
        }
    }

I need the x value only to compare it, but it runs the code again??

CodePudding user response：

I am assuming you want to create x in menu() and then store it as a variable to pass down the chain of function calls started in menu().

Under this assumption what you ought to do is simple. menu() becomes:

void menu(){
    if(kbhit()){
        char x=getch();   // CHANGED
        if(x=='s' || x=='S'){
            system("cls");
            table();
            while(Lose){
                Line();
                Input();
                Move(x);   //CHANGED
                Sleep(50);
            }
            system("pause");            
       }
   }
}

Then Move() should be modified into Move(char x):

void Move(char x){   // CHANGED
    if (HeadY >= Height-1 || HeadY <= 0 || HeadX >= Widht-1 || HeadX <= 0)
        Lose = false;
    char level = difficulty(x);   // CHANGED
    if (level=='2' || level=='3'){
        for (int i=0;i<Ta_N;i  )
            if (HeadX==Ta_X[i] && HeadY==Ta_Y[i])
                Lose = false;
    }
}

difficulty() becomes difficulty(char x)

char difficulty(char x) {   //CHANGED 
    // DELETED LINE char x;
    // REDUNDANT AS EXPLAINED IN COMMENT BELOW while (true) {
    // REDUNDANT    if (kbhit()) {
            // DELETED LINE x = getch();
    if (x == '1' || x == '2' || x == '3') {
        return x;
                // DELETE THIS break;
    } else
        throw("what happens when x != 1 or 2 or 3?");   //ADDED
    // REDUNDANT   } else
    // REDUNDANT        throw("what happens when kbhit() is false?");   
    // REDUNDANT }
    cout << "done";
}