将输入存储到数组 C++
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storing input into Arrays C++
提问by user2211678
I am learning about arrays , what I wanted to try is first let the user enter x,y values 4 times e.g
我正在学习数组，我想尝试的是首先让用户输入 x,y 值 4 次，例如
first time
第一次
x = 1
y = 3
second time
第二次
x = 2
y = 3
third time
第三次
x = 3
y = 1
fourth time
第四次
x = 1
y = 3
. and then store the value that the user had key in 4 times inside a array and print them out but I getting some weird outputs.
. 然后将用户输入的值存储在数组中 4 次并将它们打印出来，但我得到了一些奇怪的输出。
my output
我的输出
10001711642800 <-- some weird output
expected output
预期产出
1,3
2,3
3,1
1,3
code(not working)
代码（不工作）
int x;
int y;
//request the user to enter x and y value 4 times.
for (int i=1; i<5; i++) {
cout << i << "Please enter x-cord." << endl;
cin >> x;
cout <<i << "Please enter y-cord." << endl;
cin >> y;
}
//intitalize the array size and store the x,y values
int numbers[4][4] = {
x, y
};
//loop through 4 times to print the values.
for (int i = 0; i<5; i++) {
cout << numbers[i][i];
}
I know it can be done with vectors but now I am trying with arrays because I am weak in using arrays.
我知道它可以用向量来完成，但现在我正在尝试使用数组，因为我在使用数组方面很弱。
回答by Bj?rn Pollex
You are confusing a lot of things here.
你在这里混淆了很多东西。
- In your
for-loop you are overwriting the value stored inxandyat each iteration of the loop. int numbers[4][4]creates a two-dimensional array containing a total of 16 elements. What you want isint numbers[4][2].- Your array initialization is incomplete, because
xandyonly contain the last two values the user has entered, not all 8.
- 在您的
for-loop 中，您将覆盖存储在循环中x和y每次迭代中的值。 int numbers[4][4]创建一个包含总共 16 个元素的二维数组。你想要的是int numbers[4][2].- 您的数组初始化不完整，因为
x并且y只包含用户输入的最后两个值，而不是全部 8。
To fix this, you should create the array before the for-loop and then store the values the user enters directly into the array.
要解决此问题，您应该在for-loop之前创建数组，然后将用户输入的值直接存储到数组中。
回答by Mohsen Safari
use this code:
使用此代码：
int numbers[4][2];
for(int i=0;i<4;i++)
{
cout<<i<<": Please enter x-cord."<<endl;
cin>>numbers[i][0];
cout<<i<<": Please enter y-cord."<<endl;
cin>>numbers[i][1];
}
for (int i = 0; i<4; i++)
{
cout << numbers[i][0]<<" "<<numbers[i][1];
}
回答by legends2k
You're not storing the input received from the user in any array. They're overwritten again and again in the loop. Store them in an array and then display it.
您没有将从用户收到的输入存储在任何数组中。它们在循环中一次又一次地被覆盖。将它们存储在一个数组中，然后显示它。
//intitalize the array size and store the x,y values
int numbers[4][4] = {
x, y
};
This is not required. Since you're going to overwrite the contents of the array you needn't initialize them with some random variables. In fact the variables xand yare not at all required.
这不是必需的。由于您要覆盖数组的内容，因此无需使用一些随机变量初始化它们。事实上，变量x和y根本不需要。
#include <iostream>
int main(int argc, char *argv[])
{
// you need 4 arrays of 2 numbers, not 4x4 but 4x2
int numbers[4][2] = { { } }; // initialize all of them to 0
for (size_t i = 0; i < 4; ++i)
{
std::cout << "x = ";
std::cin >> numbers[i][0]; // store the input directly in the array
std::cout << "y = "; // instead of using a dummy
std::cin >> numbers[i][1];
}
// display array contents
for (size_t i = 0; i < 4; ++i)
{
std::cout << numbers[i][0] << ", " << numbers[i][1] << std::endl;
}
}
回答by Atle
First, you have to declare the variable you need to fill;
首先，你必须声明你需要填充的变量；
// A new data type which holds two integers, x and y
struct xy_pair {
int x;
int y;
};
// A new array of four xy_pair structs
struct xy_pair numbers[4];
Then, you can begin filling it.
然后，您可以开始填充它。
//request the user to enter x and y value 4 times.
for (int i=1; i<5; i++) {
cout << i << "Please enter x-cord." << endl;
cin >> numbers[i].x;
cout <<i << "Please enter y-cord." << endl;
cin >> numbers[i].y;
}
Then, you can print it!
然后就可以打印了！
//loop through 4 times to print the values.
for (int i = 0; i<5; i++) {
cout << "X is " << numbers[i].x << " and Y is " << numbers[i].y << endl;
}
PS! I haven't run the code myself, let me know if it doesn't work.
附注！我自己没有运行代码，如果它不起作用，请告诉我。
