Thread: What could be the real life example of continue statement ?

I did google search but I couldn't found the real life example of continue statement in c programming.

I have looked some example but I can't figure if the statement are useful in program

Lets look this program from the book

Code:

// C program to explain the use  // of continue statement  
#include <stdio.h> 
  
int main() { 
    // loop from 1 to 10  
    for (int i = 1; i <= 10; i++) {  
  
        // If i is equals to 6,  
        // continue to next iteration  
        // without printing  
        if (i == 6)
		{			
            continue;  
        } 
        else
		{
            // otherwise print the value of i  
            printf("%d ", i);  
		}
    }  
  
    return 0;  
}

Program gives output
1 2 3 4 5 7 8 9 10

If I remove continue statement from the code. there is nothing change happen in program out

It gives same result as it was
1 2 3 4 5 7 8 9 10

What could be the real life example of continue statement ?

Originally Posted by laserlight

That's because you've separated the logic into two branches, and in the if branch, control will continue to the next iteration regardless of whether you have the continue statement there. Try:

Not sure

Code:

// C program to explain the use  // of continue statement#include <stdio.h>


int n = 3;
 
int main() {
    // loop from 1 to 5
	
    for (int i = 0; i < 5; i++) {
 
        // If i is equals to 3,
        // continue to next iteration
        // without printing
        if (i == n)
        {
			 printf("i ==6 \n");
            continue;
        }
		
		printf("i \n");
    }
 
    return 0;
}

if I comment continue statement or If I use continue statement so both condition program give the same output

i
i
i
i ==6
i
i

What's wrong with my thinking ?

You must have read about the "break" keyword before reading about the "continue" keyword. As soon as "break" is encountered, the compiler essentially skips to the next executable statement. As soon as "continue" is encountered, instead of skipping to the next executable statement, the compiler skips that entire iteration. So, dry run the code in your mind/paper and see what the program to should be doing.

Code:

int main (void)
{
      std::cout << "Numbers from 0-9: ";

      for (int i = 0; i < 10; i++)
            std::cout << i << " ";

      int Num;

      std::cout << std::endl << "Enter a number between 0-9 that you don't want to see: "; std::cin >> Num;

      std::cout << std::endl << "Numbers from 0-9: ";

      /* It depends where you place the continue statement - 1 */
      for (int j = 0; j < 10; j++)
      {
            if (j == Num) continue;

            std::cout << j << " ";
      }

      std::cout << std::endl << "Numbers from 0-9: ";

      /* It depends where you place the continue statement - 2 */
      for (int k = 0; k < 10; k++)
      {
            std::cout << k << " ";

            if (k == Num) continue;
      }

      std::cout << std::endl << "Numbers from 0-9: ";

      /* break statement instead */
      for (int l = 0; l < 10; l++)
      {
            if (l == Num) break;

            std::cout << l << " ";
      }

      return 0;
}

Take it as an exercise and first try to predict the output yourself and write it down. The solution is below. Does it make sense now?

OUTPUT:

Code:

Numbers from 0-9: 0 1 2 3 4 5 6 7 8 9
Enter a number between 0-9 that you don't want to see: 5

Numbers from 0-9: 0 1 2 3 4 6 7 8 9
Numbers from 0-9: 0 1 2 3 4 5 6 7 8 9
Numbers from 0-9: 0 1 2 3 4

Originally Posted by Zeus_

You must have read about the "break" keyword before reading about the "continue" keyword.

Thank you
break statement

Code:

 #include <stdio.h> 
int n = 3;
 
int main() {
    // loop from 1 to 5
    for (int i = 0; i < 5; i++) {
		
		    if (i == n) 
				break;
 
            printf("i = %d \n", i);
    }
 
    return 0;
}

i = 0
i = 1
i = 2


continue statement

Code:

#include <stdio.h>
 
int n = 3;
 
int main() {
    // loop from 1 to 5
    for (int i = 0; i < 5; i++) {
		
		    if (i == n) 
				continue;
 
            printf("i = %d \n", i);
    }
 
    return 0;
}

i = 0
i = 1
i = 2
i = 4

It's nice that you understand how it works now. A real life example of where you might wanna use continue is when you're deleting records in a file using a temporary file. You iterate and copy all the contents of one file to the other except for the one which you want to be deleting (where you'd be using a check in your iterations and as soon as the check results to true, you continue instead of writing into the temp file). Then you delete the old file and rename the temporary file to whatever the old file was called.