Break and Continue

Disipal · 04-09-2009, 05:09 PM

Continue and break are used within PHP loops (for, while, foreach, do-while and switch) to skip iterations and exit the loops respectively.
break

break is used to exit a loop and is used like this:

PHP Code:


			
<?php 
$array = array('pizza', 'burger', 'chips', 'pasta', 'kebab'); 

foreach($array as $food) 
{ 
    if($food == 'chips') 
    { 
        break; 
    } 

    echo $food . '<br />'; 

} 
echo 'End of foods'; 
?>

This will output:

PHP Code:


			
pizza
burger
End of foods

So what is happening? When the current $food is equal to chips a break statement is encountered. This causes the foreach loop to stop executing and PHP continues from the end of the foreach loop at the echo statement which outputs "End of foods".
Nested loops

Using break alone will exit the current loop. break accepts an optional argument which tells it how many nested loops to exit from. For example:

PHP Code:


			
<?php 
$array = array('pizza', 'burger', 'chips', 'pasta', 'kebab'); 

for($i = 1; $i <= 2; $i++) 
{ 
    foreach($array as $food) 
    { 
           if($food == 'chips') 
           { 
                    break 1; 
            } 

        echo $food . '<br />'; 
    } 
     
    echo 'End of foods ' . $i . ' <br />'; 
} 
echo 'End of foods'; 
?>

break 1 is the same as just using break alone. So this code will only exit the inner foreach loop giving an output like this:

PHP Code:


			
pizza
burger
End of foods 1 
pizza
burger
End of foods 2 
End of foods

In order to exit both the inner foreach loop and outer for loops simply increase the argument of break to 2:

PHP Code:


			
<?php 
$array = array('pizza', 'burger', 'chips', 'pasta', 'kebab'); 

for($i = 1; $i <= 2; $i++) 
{ 
    foreach($array as $food) 
    { 
           if($food == 'chips') 
           { 
                    break 2; 
            } 

        echo $food . '<br />'; 
    } 
     
    echo 'End of foods ' . $i . ' <br />'; 
} 
echo 'End of foods'; 
?>

This will output:

PHP Code:


			
pizza
burger
End of foods

This time both the foreach and for loops are exited when the break is found and so the list of foods is only outputted once before continuing from the end of the for loop.
continue

When a continue statement is encountered in a loop the loop skips to the next iteration. Here is a simple example to demonstrate this behaviour:

PHP Code:


			
<?php 
for($i = 1; $i <= 5; $i++) 
{ 
    if($i == 3) 
    { 
        continue; 
    } 
     
    echo $i . '<br />'; 
} 
?>

This PHP code outputs:

PHP Code:

When $i is 3 the continue statement causes the loop to skip any further code in the loop and return to the start.
Nested loops

Like break, the continue keyword can take an optional argument to skip nested loops. Take this example:

PHP Code:


			
<?php 
for($j = 10; $j <= 30; $j += 10) 
{ 
    echo $j . '<br />'; 
     
    for($i = 1; $i <= 5; $i++) 
    {     
        if($i == 3) 
        { 
            continue 2; 
        } 
     
        echo $i . '<br />'; 
    } 
} 
?>

This code results in this output:

PHP Code:

When the inner loop, $i, reaches 3 the continue statement, with an argument of 2, breaks out of both the inner and outer loops. PHP then returns to the start of the outer loop again.

Ashlyn · 03-12-2010, 10:26 AM

One of my friends refer me to this forum and I really enjoyed it

04-09-2009, 05:09 PM	#1 (permalink)
Disipal Administrator Join Date: Mar 2009 Location: Athens (Greece) Posts: 220	Break and Continue Continue and break are used within PHP loops (for, while, foreach, do-while and switch) to skip iterations and exit the loops respectively. break break is used to exit a loop and is used like this: PHP Code: `<?php $array = array('pizza', 'burger', 'chips', 'pasta', 'kebab'); foreach($array as $food) { if($food == 'chips') { break; } echo $food . '<br />'; } echo 'End of foods'; ?>` This will output: PHP Code: `pizza burger End of foods` So what is happening? When the current $food is equal to chips a break statement is encountered. This causes the foreach loop to stop executing and PHP continues from the end of the foreach loop at the echo statement which outputs "End of foods". Nested loops Using break alone will exit the current loop. break accepts an optional argument which tells it how many nested loops to exit from. For example: PHP Code: `<?php $array = array('pizza', 'burger', 'chips', 'pasta', 'kebab'); for($i = 1; $i <= 2; $i++) { foreach($array as $food) { if($food == 'chips') { break 1; } echo $food . '<br />'; } echo 'End of foods ' . $i . ' <br />'; } echo 'End of foods'; ?>` break 1 is the same as just using break alone. So this code will only exit the inner foreach loop giving an output like this: PHP Code: `pizza burger End of foods 1 pizza burger End of foods 2 End of foods` In order to exit both the inner foreach loop and outer for loops simply increase the argument of break to 2: PHP Code: `<?php $array = array('pizza', 'burger', 'chips', 'pasta', 'kebab'); for($i = 1; $i <= 2; $i++) { foreach($array as $food) { if($food == 'chips') { break 2; } echo $food . '<br />'; } echo 'End of foods ' . $i . ' <br />'; } echo 'End of foods'; ?>` This will output: PHP Code: `pizza burger End of foods` This time both the foreach and for loops are exited when the break is found and so the list of foods is only outputted once before continuing from the end of the for loop. continue When a continue statement is encountered in a loop the loop skips to the next iteration. Here is a simple example to demonstrate this behaviour: PHP Code: `<?php for($i = 1; $i <= 5; $i++) { if($i == 3) { continue; } echo $i . '<br />'; } ?>` This PHP code outputs: PHP Code: `1 2 4 5` When $i is 3 the continue statement causes the loop to skip any further code in the loop and return to the start. Nested loops Like break, the continue keyword can take an optional argument to skip nested loops. Take this example: PHP Code: `<?php for($j = 10; $j <= 30; $j += 10) { echo $j . '<br />'; for($i = 1; $i <= 5; $i++) { if($i == 3) { continue 2; } echo $i . '<br />'; } } ?>` This code results in this output: PHP Code: `10 1 2 20 1 2 30 1 2` When the inner loop, $i, reaches 3 the continue statement, with an argument of 2, breaks out of both the inner and outer loops. PHP then returns to the start of the outer loop again.

03-12-2010, 10:26 AM	#2 (permalink)
Ashlyn Junior Member Join Date: Mar 2010 Posts: 1	Re: Break and Continue One of my friends refer me to this forum and I really enjoyed it __________________ read more about a+ certification and ccna security as well about mcts

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode