On the first day of clock in, click to open a surprise, and the switch statement is explained in detail

#include<stdio.h>
int main ()
{
    int n=1;
    int m=2;
    switch(n)
    {
    case 1: m++;
    case 2: n++;
    case 3:
        switch(n)
        {//switch Allow nesting 
        case 1: n++;
        case 2: m++; 
                n++; 
                break;
        }
    case 4: m++;
        break;
    default:
        printf(" Input error "); 
    }
    printf("m=%d, n=%d",m,n);
    return 0;
}

Guess the result of this string of code

Are you right ？

If you don't

Just take a good look at my following explanation ！

switch（ Shaping expression ）// It's very important here. It must be an integer expression , If it is float=1.0, Then the code will make an error             {                                                                                                                                                                  Statement item ;                                                                                                                                       }

And statement items are just some case sentence

case Equivalent to entering switch The gate of statement

case  Integral constant expression ;// If appear case 1.0\case n, Sorry, there will be an error in the code                                          sentence ;

break It's about jumping out switch Key  

As the above question

n Get into switch from case 1 Compile down to case 2,case 3（ As long as you don't meet break）

If you think this way , Sorry , Be careful next time ！

switch (n) The point is n, This n Decide from which case Door in , As long as you don't encounter break, Our integer will be right all the way down

  switch(n)
    {
    case 1: m++;
    case 2: n++;
    case 3:
        switch(n)
        {//switch Allow nesting
        case 1: n++;
        case 2: m++; 
                n++; 
                break;
        }

these two items. switch（n） Just two gates , first n=1 Input , From case 1 Go down to case 3 At this time, some cute people, like me, started from case 1 Go down , Click down , Sorry , Be careful next time ！

When it comes to the second switch（n） when n Already in case 2 Evolved into 2 了 , So it goes directly from case 2 Down met break, encounter break It's another pit .

It says break It's like a key to go out , But a key can only open one door , It can only make your program pop up the nearest “  }  ”, The program will still go down , Until the last one pops up “  }  ”.

If you are serious enough to read this article I wrote , I will be very moved , Because I don't want to read it anymore , Ha ha ha ！ Thank you for clicking into my article , thank you ！