Creating a PHP Looping Statement
By Darren W. Hedlund2005-03-29
PHP Loops
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Creating a PHP Looping Statement
Creating a PHP loop to go through a certain part of code to gather more information than just a single part of data is essential to many programmers.
These methods are used for searching iside a database, counting through information, and other useful functions.
Below are some simple ways that you can create a while lopp in PHP.
• while - loops through a block of code as long as a specified condition is true
• do...while - loops through a block of code once, and then repeats the loop as long as a special condition is true
• for - loops through a block of code a specified number of times
• foreach -
The while Statement
The while statement will execute a block of code if and as long a condition is true.
Syntax
while (condition)
code to be executed;
Example
The following example demonstrates a loop that will continue to run as long as the variable i is less than, or equal to 5. i will increase by 1 each time the loop runs:
<html>The do...while Statement
<body><?php
$i=1;
while($i<=5)
{
echo "The number is " . $i . "<br />";
$i++;
}
?></body>
</html>
The do...while statement will execute a block of code at least once - it then will repeat the loop as long as a condition is true.
Syntax
doExample
{
code to be executed;
}
while (condition);
The following example will increment the value of i at least once, and it will continue incrementing the variable i while it has a value of less than 5:
<html>The for Statement
<body><?php
$i=0;
do
{
$i++;
echo "The number is " . $i . "<br />";
}
while ($i<5);
?></body>
</html>
The for statement is used when you know how many times you want to execute a statement or a list of statements.
Syntax
for (initialization; condition; increment)Note: The for statement has three parameters. The first parameter is for initializing variables, the second parameter holds the condition, and the third parameter contains any increments required to implement the loop. If more than one variable is included in either the initialization or the increment section, then they should be separated by commas. The condition must evaluate to true or false.
{
code to be executed;
}
Example
The following example prints the text "Hello World!" five times:
<html>
<body><?php
for ($i=1; $i<=5; $i++)
{
echo "Hello World!<br />";
}
?></body>
</html>
Tutorial Pages:
» PHP Loops
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