5. Difference between break and continue (easy to understand version)

break and continue All of them are used in circular statements , Whether it's for loop , still while loop , Or is it do…while The loop can jump out of the loop .

The difference is

1.continue sentence Just end this cycle , Instead of ending the cycle . That is, skip the following unexecuted statements in the loop body , Then, it is determined whether to execute the cycle next time .

2.break The sentence is End the cycle , It is no longer necessary to judge whether the conditions for executing the loop are true . however break You can only jump out of a loop . When there are multiple nested loops ,break Can only jump out of “ The parcel ” Its innermost layer of circulation , Can't jump out of all loops at once .

Let's first understand through a simple program .

1. We use break To jump out of the loop .

int main(int argc, char const *argv[])
{
   
    for (int i = 1; i <= 5; i++)
    {
        if (i == 4)
        {
            break;
            // continue;
        }
        printf("i=%d\n", i);
    }

    return 0;
}

  Through the output, we know , stay i=4 When ,break Directly jumped out of this for loop , No longer judge whether the loop can be executed .

2. We use continue To jump out of the loop

int main(int argc, char const *argv[])
{
   
    for (int i = 1; i <= 5; i++)
    {
        if (i == 4)
        {
            //break;
            continue;
        }
        printf("i=%d\n", i);
    }

    return 0;
}

We can see that , stay i=4 When , Just jump out of this cycle , But will then enter this for loop , Instead of completely jumping out for loop .

But we must remember , In a nested loop ,break Just jumped out of the cycle that wrapped it , And the loop nested outside it cannot jump out . We are looking at it through an example .

int main(void)
{
    int val; // Defining variables val, Represents the floor 
    while (1)
    {
        printf(" Please enter the floor you want to go to :");
        scanf("%d", &val);
        switch (val)
        {
        case 1:
            printf("1 Stratification !\n");
            break; // Jump out of switch
        case 2:
            printf("2 Stratification !\n");
            break; // Jump out of switch
        case 3:
            printf("3 Stratification !\n");
            break; // Jump out of switch
        default:
            printf(" This layer does not exist ,  Please re-enter :");
            break;
        }
    }
    return 0;
}

  Here we can see Wrap it directly break The cycle is switch, instead of while, If you jump out of the loop, you just jump out switch, Can't jump out while, in other words while The statement will also execute .

Through the output, we can see ,break Can only jump out of switch The cycle of , And can't jump out of while This cycle , because while Not directly wrapped break The cycle of