在 for 循环中使用 1 个以上的值？

Question

I need help to use a 'for loop' with more than 2 values which are going together. This is my code:

for( x=1 , y=1 ; x<6 , y<10 ; x++  , y++){
    cout << "x:" << x << endl;
    cout << "y:" << y << endl;

Right now when I run it ... x and y are going up to 9 although I want them to run together but i want x to stop outputting at 6 and i want y to continue to 9..but I don't know how to do it or is it even possible to do so.. Thanks in advance!

Answer 1

I don't use c++ so someone correct me if my syntax is wrong, but as a broad-spectrum programmer I'd imagine the solution would look something like this:

for (x=1, y=1; x<6 || y<10;) {
    if (x<6) {
        cout << "x:" << x << endl;
        ++x;
    }
    if (y<10) {
        cout << "y:" << y << endl;
        ++y;
    }
}

There are also ways to achieve this affect without leaving the core of your for loop using ternary operators but for the sake of simplicity I've excluded that here.

Answer 2

test.cpp:

#include <iostream>
int main() {
    for(int i = 1; i < 6; ++i) {
        std::cout << "x: " << i << std::endl;
        std::cout << "y: " << i << std::endl;
    }
    for(int i = 6; i < 10; ++i) {
        std::cout << "y: " << i << std::endl;
    }
}

Output:

x: 1
y: 1
x: 2
y: 2
x: 3
y: 3
x: 4
y: 4
x: 5
y: 5
y: 6
y: 7
y: 8
y: 9

Answer 3

The simplest, for a natural interpretation of the question, is a nested loop:

for( int y = 1; y < 10; ++y )
{
    for( int x = 1; x < 6; ++x )
    {
        cout << "x:" << x << endl;
        cout << "y:" << y << endl;
    }
}

If instead you actually want two values called x and y that are always the same, and you want to do one thing for x < 6 and something else for y < 10 , then a single loop counter suffices:

for( int i = 1; i < 10; ++i )
{
    int const y = i;
    if( i < 6 )
    {
        int const x = i;
        // Do the x and y thing here. E.g.
        cout << "x: " << x << endl;
    }
    // Do the y only thing here. E.g.
    cout << "y: " << y << endl;
}

If you meant something else then you need to clarify your question, eg with an example of desired output.