Dart Break and Continue

Loop statements are used to change the normal sequence of flow of the program.

Dart supports two types of loop control statements:

• Break Statement
• Continue Statement

Break Statement :

The ‘ break ’ statement is used to terminate out the regular flow of the program. It this statement is used within a loop then as soon as the compiler encounters this statement, it terminates the loop. The flow will transfer to the immediate next statement after the loop.

Consider the syntax of using break statement :

Syntax:

break ;

Consider the following example in Dart that explains the concept of break statement.

Example 1 : Using break inside while loop

void main( )
{
    int ctr = 1 ;
  
    while ( ctr <= 5 ) 
    {
        print( " You are inside the loop, right now ! " ) ;
        print( ctr ) ;
        ctr ++ ;
  
        if ( ctr == 5 ) 
        {
            break ;
        }
    }
    print( " Now you are out of the loop because of break statement ! " ) ;
}

Output :

You are inside the loop, right now ! 
1
 You are inside the loop, right now ! 
2
 You are inside the loop, right now ! 
3
 You are inside the loop, right now ! 
4
 Now you are out of the loop because of break statement!

Explanation :

Initially the value of counter variable ‘ ctr ’ is 1 and before transferring the flow inside the loop, a condition is checked. Till ( ctr <= 4 ), the control remains inside the loop and the print( ) statement is executed. When ( ctr == 4 ), the compiler encounters the break statement, the flow comes out of the loop and the statement immediately after the loop gets executed.

Consider the following example that explains the concept ofs Dart do… while loop

Example 2 : Using break inside do..while loop

void main( )
{
    int ctr = 1 ;
    do 
       {
        print( " You are inside the loop, right now ! " ) ;
        print( ctr ) ;
        ctr ++ ;
          if ( ctr == 4 ) 
       {
            break ;
        }
    } while ( ctr <= 5 ) ;
    print( " Now you are out of the loop because of break statement ! " ) ;
}

Output :

You are inside the loop, right now ! 
1
 You are inside the loop, right now ! 
2
 You are inside the loop, right now ! 
3
 Now you are out of the loop because of break statement ! 

Continue Statement:

As you have studied so far, the ‘ break ’ statement is used to terminate the flow out of the loop. The ‘ continue ’ statement has opposite functionality, it is used to continue the flow of control. When a continue statement is encountered in a loop it doesn’t terminate the loop but rather jump the flow to next iteration.

Consider the syntax of using continue statement :

Syntax :

continue ;

Example 1 : Using continue inside while loop

void main( )
{
    int ctr = 0 ;
  
    while ( ctr <= 10 ) 
    {
        ctr ++ ;
  
        if ( ctr == 4 ) 
        {
            print( " Now you are inside the loop. 4 is printed. " ) ;
            continue ;
        }
  
        print( " You are still in the loop. Here is the counter updation : " ) ;
        print( ctr ) ;
    }
    print( " You are out of the while loop ! " ) ;
}

Output :

You are still in the loop. Here is the counter updation : 
 1
 You are still in the loop. Here is the counter updation : 
 2
 You are still in the loop. Here is the counter updation : 
 3
 Now you are inside the loop. 4 is printed. 
 You are still in the loop. Here is the counter updation : 
 5
 You are still in the loop. Here is the counter updation : 
 6
 You are still in the loop. Here is the counter updation : 
 7
 You are still in the loop. Here is the counter updation : 
 8
 You are still in the loop. Here is the counter updation : 
 9
 You are still in the loop. Here is the counter updation : 
 10
 You are still in the loop. Here is the counter updation : 
 11
 You are out of the while loop !

Explanation :

Here control flow of the loop will go smooth but when count value becomes 4 the if condition becomes true and the below statement is skipped because of continue and next iteration skipping number 4.

Example 2 : Using continue inside do..while loop

void main( )
{
    int ctr = 0 ;
  
    do {
        ctr ++ ;
  
        if ( ctr == 4 ) 
        {
            print( " Now you are inside the loop. 4 is printed. " ) ;
            continue ;
        }
      
        print( " You are still in the loop. Here is the counter updation : " ) ;
        print( ctr ) ;
      
    } while ( ctr <= 10 ) ;
  
    print( " You are out of while loop. " ) ;
}

Output :

 You are still in the loop. Here is the counter updation : 
 1
 You are still in the loop. Here is the counter updation : 
 2
 You are still in the loop. Here is the counter updation : 
 3
 Now you are inside the loop. 4 is printed. 
 You are still in the loop. Here is the counter updation : 
 5
 You are still in the loop. Here is the counter updation : 
 6
 You are still in the loop. Here is the counter updation : 
 7
 You are still in the loop. Here is the counter updation : 
 8
 You are still in the loop. Here is the counter updation : 
 9
 You are still in the loop. Here is the counter updation : 
 10
 You are still in the loop. Here is the counter updation : 
 11
 You are out of while loop.