如何打破嵌套的foreach循环然后转到c＃上的父foreach循环

Question

I have the following code:

foreach(// Some condition here)
{
    while (// Some condition here)
    {
        foreach (// Some condition here)
        {
             if (// Condition again)
             {
                  //Do some code
             }
             if (// Condition again)
             {
                 //Stop the first foreach then go back to first foreach
             }
        }
    }
}

What I want to do is when I hit the 2nd if statement on the last foreach loop is to return on the first foreach loop.

Note: If the 2nd if statement is not true, it should continue the last foreach loop until the condition is not true.

Thanks in advance!

Answer 1

The only way to this directly is with a goto .

Another (better) option is to restructure until the problem goes away. For instance by putting the inner code (while + foreach) in a method and use return to get back.

Answer 2

Something like this:

resetLoop = false;
for(// Some condition here)
{
    while (// Some condition here)
    {
        foreach (// Some condition here)
        {
             if (// Condition again)
             {
                  //Do some code
             }
             if (// Condition again)
             {
                 //Stop the first foreach then go back to first foreach
                 resetLoop = true;
                 break;
             }
        }
        if (resetLoop) break;
    }
    if (resetLoop) {
        // Reset for loop to beginning
        // For example i = 0;
    }
}

Answer 3

Noone has mentioned it (Henk mentioned briefly) yet but the best approach would be to move your loops into its own method and use return

public ReturnType Loop(args)
{
foreach outerloop
    foreach innerLoop
       if(Condition)
          return;
}

Answer 4

As i see you accepted the answer in which the person refers you goto statement, where in modern programming and in expert opinion goto is a killer, we called it a killer in programming which have some certain reasons, which i will not discuss it over here at this point, but the solution of your question is very simple, you can use a Boolean flag in this kind of scenario like i will demonstrate it in my example:

foreach(// Some condition here)
{
    //solution
    bool breakme = false;

    while (// Some condition here)
    {
        foreach (// Some condition here)
        {
            if (// Condition again)
            {
                //Do some code
            }
            if (// Condition again)
            {
                //Stop the first foreach then go back to first foreach
                breakme = true;
                break;
            }
        }
    }
    if(breakme)
    {
        break;
    }
}

simple and plain. :)

Answer 5

As said before me, I also recommend to re-factor the code and see if it is absolutely necessary to have 3 loops nested one in another. If it is, and I assume there is some logic involve, you should consider splitting into sub functions (as suggested)

For a simple code solution:

foreach(// Some condition here)
{
    var broke = false;
    while (// Some condition here)
    {
        foreach (// Some condition here)
        {
             if (// Condition again)
             {
                  //Do some code
             }
             if (// Condition again)
             {
                 //Stop the first foreach then go back to first foreach
                 broke = true;
                 break;
             }
        }
        if (broke) break;
        // continue your while loop
    }
}

Answer 6

var broken = false;
foreach(// Some condition here)
{
    broken = false;
    while (!broken && // Some condition here)
    {
        foreach (// Some condition here)
        {
             if (// Condition again)
             {
                 //Do some code
             }
             if (// Condition again)
             {
                 //Stop the first foreach then go back to first foreach
                 broken = true;
                 break;
             }
        }
    }
}