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PHP ForEach Loop

Hiroshi — Fri, 20 Jun 2008 21:27:17 +0000

PHP provides an easy way to use every element of an array with the For each statement. For each executes the code at each item in the specified array. While a For Loop and While Loop will continue until some condition fails, the For Each loop will continue until it has gone through every item in the array.

We have an associative array that stores the names of people in a company as the keys with the values being their age. We want to know how old everyone is at work so we use a Foreach loop to print out everyone’s name and age.


$employeeAges;
$employeeAges["Imran"] = "18";
$employeeAges["Kamran"] = "26";
$employeeAges["Jawad"] = "35";
$employeeAges["Javed"] = "36";
$employeeAges["Rashid"] = "32";
 
foreach( $employeeAges as $key => $value)
{
	echo "Name: $key, Age: $value 
";
}
 
// Output:
// Name: Imran, Age: 18
// Name: Kamran, Age: 26
// Name: Jawad, Age: 35
// Name: Javed, Age: 36
// Name: Rashid, Age: 32
?>

PHP ForEach Loop is a post from: PHP Magic Book - Free PHP Scripts, Tutorials and Downloads

PHP Do While Loop

Hiroshi — Fri, 20 Jun 2008 21:14:45 +0000

A “do while” loop is a slightly modified version of the while loop. A do-while loop first do’s and secondly checks the while condition!

PHP Do While Loop Structure

- Define
- Do
- Print
- Increment or decrement
- Condition

PHP Do While Loop Example


$num = 1;
do
{
echo $num;
$num = $num + 1;
$num++;
}
while($num < 10)
 
// Output: 13579
 
?>

Displaying the numbers from 1 to 10, with their squares


$count = 1;
do
{
  $square = $count * $count;
  echo "$count squared is $square 
";
  $count++;
}
while ($count <= 10);
 
// Output:
// 1 squared is 1
// 2 squared is 4
// 3 squared is 9
// 4 squared is 16
// 5 squared is 25
// 6 squared is 36
// 7 squared is 49
// 8 squared is 64
// 9 squared is 81
// 10 squared is 100
?>

PHP Do While Loop is a post from: PHP Magic Book - Free PHP Scripts, Tutorials and Downloads

PHP While Loop

Hiroshi — Fri, 20 Jun 2008 21:07:11 +0000

The while keyword takes a condition in parentheses, and the code block that follows is repeated while that condition is true. If the condition is false initially, the code block will not be repeated at all.

The repeating code must perform some action that affects the condition in such a way that the loop condition will eventually no longer be met; otherwise, the loop will repeat forever. Such loops are Infinite Loops.

Structure Of PHP While Loop

- Define
- Condition
- Print
- Increment or decrement

while ( conditional statement is true)
{
	//do the task;
}

PHP While Loop Example


$num = 3;
while($num < 10)
{
echo $num;
$num = $num + 1;
$num++;
}
 
// Output: 3579
 
?>


$count = 1;
while ($count <= 10) {
  $square = $count * $count;
  echo "$count squared is $square 
";
  $count++;
}
 
// Output:
// 1 squared is 1
// 2 squared is 4
// 3 squared is 9
// 4 squared is 16
// 5 squared is 25
// 6 squared is 36
// 7 squared is 49
// 8 squared is 64
// 9 squared is 81
// 10 squared is 100
 
?>

PHP While Loop is a post from: PHP Magic Book - Free PHP Scripts, Tutorials and Downloads

PHP For Loop

Hiroshi — Fri, 20 Jun 2008 19:46:11 +0000

For loop consists of three phases. i.e.

Define
Condition
Increment or decrement

First we define something. Then we apply a condition and then under that condition we increment or decrement that defined thing.

In complex way;
- The first part is an expression that is evaluated once when the loop begins.
- The second part is the condition. While the condition is true, the loop continues repeating. If the condition is false to start with, the following code block is not executed at all.
- The third part is an expression that is evaluated once at the end of each pass of the loop.

for ( initialize a counter;
       conditional statement;
       increment a counter)
{
	do this code;
}

Examples


for ($i = 1; $i <= 10; $i++)
{
    echo $i;
}
 
// Output of this script will be. 12345678910
 
// Explanation of above example:
// In this we define a var i and give it a value of 1.
// We tell the script to increment the value of i and print it.
// And keep incrementing it and printing it until it reaches to the value of 10.
// Or keep incrementing it and printing it if it is less then 10 or equal to 10.
 
// Caution:
// Now do not run a loop without a condition.
// Because it can go pretty mad without a condition.
// and go in cyclic chain process which will never end.
// and your PC or at least your PHP host will be held.
?>

Other Examples Of For Loop In PHP


for ($i = 1; $i <= 10; print $i, $i++);
 
// Output of this script will be. 12345678910
 
?>


$i = 1;
for (; ; )
{
    if ($i > 10)
   {
        break;
    }
    echo $i;
    $i++;
}
 
// Output of this script will be. 12345678910
 
?>


for ($i = 1; ; $i++)
   {
    if ($i > 10) {
        break;
    }
    echo $i;
}
 
// Output of this script will be. 12345678910
 
?>


for($num = 1; $num < 10; $num++)
{
if($num == 5)
continue;
echo "\n" . $num;
}
 
// Output of this script will be. 1 2 3 4 6 7 8 9
 
?>


for($num = 1; $num < 10; $num++)
{
if($num == 5)
break;
echo "\n" . $num;
}
 
// Output of this script will be. 1 2 3 4
 
?>

Using PHP for loop allows you to use much less code to do the same thing as with while and do.

PHP For Loop is a post from: PHP Magic Book - Free PHP Scripts, Tutorials and Downloads

For Loop in PHP

Hiroshi — Thu, 19 Jun 2008 00:10:13 +0000

I am describing for loop with an example that include randomizing number display using images from a directory. Use following script and create a folder nb and put images 0.gif, 1.gif, … , 9.gif containing same digit over each and see.

PHP Code


$mynumber= rand(1111111111,9999999999);
// echo $mynumber;
$ilength=strlen($mynumber);
for($i=0; $i<$ilength; $i++)
{
$ipic= substr($mynumber, $i, 1);
$sFilePath = "";
if (file_exists("nb/".$ipic.".gif"))
$sFilePath = "nb/".$ipic.".gif";
?>
 $sFilePath ?>">

}
?>

For Loop Rand Numbers Script Download

For Loop in PHP is a post from: PHP Magic Book - Free PHP Scripts, Tutorials and Downloads

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