How to break out of multiple loops at once in C#?

问题

What if I have nested loops, and I want to break out of all of them at once?

while (true) {
    // ...
    while (shouldCont) {
        // ...
        while (shouldGo) {
            // ...
            if (timeToStop) {
                break; // Break out of everything?
            }
        }
    }
}

In PHP, break takes an argument for the number of loops to break out of. Can something like this be done in C#?

What about something hideous, like goto?

// In the innermost loop
goto BREAK
// ...
BREAK: break; break; break;

回答1:

Extract your nested loops into a function and then you can use return to get out of the loop from anywhere, rather than break.

回答2:

Introduce another control flag and put it in all your nested while condition like below. Also replaces the while(true) condition you have with that

bool keepLooping = true;
while (keepLooping) {
    // ...
    while (shouldCont && keepLooping) {
        // ...
        while (shouldGo && keepLooping) {
            // ...
            if (timeToStop) { 
                keepLooping  = false;
                break; // break out of everything?
            }
        }  
    }
}

回答3:

Goto is only hideous when abused. To drop out of the innermost loop of some nesting it's acceptable. BUT... one has to ask why there is so much nesting there in the first place.

Short answer: No.

回答4:

If you want to break out of an entire method, then use the code below. If you only want to break out of a series of loops within a method without breaking out of the method, then one of the answers that have already been posted will do the job.

if (TimeToStop)
{
   return;
}

来源：https://stackoverflow.com/questions/2339142/how-to-break-out-of-multiple-loops-at-once-in-c

标签

loops

goto

break