The for loop in PHP. Syntax and array iteration. Code example

The for loop has the following formal definition:

for ([counter initialization]; [condition]; [counter change])
{
     // actions
}

example for loop:

for ($i = 1; $i < 10; $i++)
{
    echo $i;
}

Parts of the for loop declaration may be missing. For example, there is no counter definition (it can be defined outside the loop):

$m = 5;
for (; $m < 10; $m++)
{
    echo $m;
}

Changing the counter value and change it inside the loop:

$i = 0;
for (; $i < 10;)
{
    echo $i;
    $i += 2;
}

Also, you can define and use several variables in the loop declaration at once:

for ($i =1, $m=1; $i + $m < 100; $i++, $j+=10)
{
    echo "$i + $m = " . $i + $m ";
}

alternative syntax:

for ($i = 1; $i < 10; $i++):
    echo  $i * $i";
endfor;

Iterating the array using the for loop

//create array
$array[] = '1';
$array[] = '2';
$array[] = '3';

//count array length
$count = count($array);

//pass the array
for ($i=0; $i<$count; $i++)
{
    echo $array[$i];	
}

Pass associative array using the for loop

reset() – sets the pointer to the first element of the array;

next() – moves the pointer forward one element of the array;

key() – returns the key of the current array element.

$array['One'] = 1;
$array['Two'] = 2;
$array['Three'] = 3;
for (reset($array); ($key = key($array)); next($array))
{
    echo $key. '=&gt;' .$array[$key] . '<br>';	
}