如何将值添加到数组而不在 for 循环外将它们重置为 0

Question

我正在尝试编写将 3 项添加到数组的代码，然后查找任何对。然而，当 for 循环结束时，数组只是重置为 {0,0,0}。我如何 "save" 数组值以便它们在退出循环后不重置？

    srand(seed);
    const int RANDOMS_NEEDED = 3;
    int rando = 0;
    int rando_max = 10;
    int slotsOutput[3] = {};
    cout << "\t Generating random numbers from 0 to " << rando_max << endl << "\t";

    for (int i = 0; i < RANDOMS_NEEDED; i++) {
        int slotsOutput[3] = {};
        rando = rand();
        int randoInRange = rando % (rando_max + 1);
        cout << "|  " << randoInRange << "  |";
        slotsOutput[i] = randoInRange;
        Sleep(500);
        cout << slotsOutput[i];
        }

Answer 1

How do I "save" the array values so they dont reset after exiting the loop?

您需要删除在循环内重置数组的代码 - 它应该已经在循环外完成。

for (int i = 0; i < RANDOMS_NEEDED; i++) {
    int slotsOutput[3] = {};  //<-- remove

Answer 2

在for循环内，声明一个新数组slotsOutput，与循环外的变量同名。循环内的操作只影响第二个数组，它通过具有相同的名称隐藏第一个数组。当循环退出时，第二个数组消失，您可以访问第一个数组，它没有改变。

如果您启用了适当的警告级别，您的编译器应该对此发出警告。

Answer 3

在for循环中，你是shadowing你预先声明的变量slotsOutPut。

int slotsOutput[3] = {}; // Declares here

...

for (int i = 0; i < RANDOMS_NEEDED; i++) {
        int slotsOutput[3] = {}; // Declared again, which shadows above slotsOutPut

你所做的只是简单的。

int asdf = 3; // asdf is 3 here
{
    int asdf = 4; // asdf is 4 here, but it's different asdf to above one.
    cout << asdf; // prints 4
} // local variable asdf is gone with the end of the scope.
cout << asdf; // prints 3

看来您必须删除 for 循环中的行 int slotsOutput[3] = {};。

如何将值添加到数组而不在 for 循环外将它们重置为 0

How do I add values to an array without them resetting to 0 outside the for loop

c++

arrays

random-seed