Iterative statements (loops concepts) in php

Explain about PHP looping?
Looping statements are used in PHP to execute the code for a developer defined number of times.
PHP has these following looping statements they are
- while() loop,
- do while() loop,
- for() loop and
- foreach() loop

/* Example for while() loop */
echo "Example using while() loop to display 1-4 numbers
";
$i=1;
while($i<5){
echo $i." ";
$i++;
}

echo "
Example using do-while() loop to display 1-4 numbers
";
/* Example for do-while() loop */
$i=1;
do {
echo $i." ";
$i++;
}while($i<5);

echo "
Example using for() loop to display 1-4 numbers
";
/* Example for for() loop */
for($i=1;$i<5;$i++){
echo $i." ";
}

echo "
Example using foreach() loop to display 1-4 numbers
";
/* Example for for() loop */
$a = array(1,2,3,4);
foreach($a as $i){
echo $i." ";
}
?>