As far as my knowledge is concerned, I never use it almost for array traversal. I will do it for other types of iterations. But for each is just too easy. The execution time difference is very minimal in most scenarios.
It is very surprising things to watch here:
for($i =0; $i < count($array); $i++){
This loop is a very expensive loop. it calls count on every single iteration.
As for the iterators, for each is equivalent to:
$it->get();
while($it->true()){
$key = $it->key();// If using the $key => $value syntax
$value = $it->current();
// Contents of the loop in here
$it->next();
}
As far as faster ways to iterate is concerned, it just depends on the problem.
Remember, Premature Optimization Is The Root Of All Evil.
This is the below example, based on the practical executions time taken;
$a = array();
for($i =0; $i <10000; $i++){
$a[]= $i;
}
$start = microtime(true);
foreach($a as $k => $v){
$a[$k]= $v +1;
}
echo “Completed in “, microtime(true)– $start,” Seconds\n”;
$start = microtime(true);
$start = microtime(true);
foreach($a as $k =>&$v){
$v = $v +1;
}
echo “Completed in “, microtime(true)– $start,” Seconds\n”;
$start = microtime(true);
foreach($a as $k => $v){}
echo “Completed in “, microtime(true)– $start,” Seconds\n”;
$start = microtime(true);
foreach($a as $k =>&$v){}
echo “Completed in “, microtime(true)– $start,” Seconds\n”;
output :
Completedin0.0073502063751221Seconds
Completedin0.0019769668579102Seconds
Completedin0.0011849403381348Seconds
Completedin0.00111985206604Seconds
This is another example of providing script execution time.
By using a for loop :
for($i=0; $i<100000; $i++)
{
//Do Something
}
Using a while loop
$i=0;
while($i<100000)
{
//do something
$i++;
}
Using a do while loop :
$i=0;
do
{
//do something
$i++;
} while($i<100000);
Output
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