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PHP Loops

When you write code, you want the same block of code to run over and over again in a row. Instead of adding several almost equal code-lines in a script, we can use loops to perform a task like this. A Loop is an Iterative Control Structure that involves executing the same number of code a number of times until a certain condition is met. The basic idea behind a loop is to automate the repetitive tasks within a program to save the time and effort.<br><br>https://www.ducatindia.com/phptraining/

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PHP Loops

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  1. Welcome To Best Training Institute 70-70-90-50-90 www.ducatindia.com info@ducatindia.com

  2. Looping (Iteration) When you write code, you want the same block of code to run over and over again in a row. Instead of adding several almost equal code-lines in a script, we can use loops to perform a task like this. A Loop is an Iterative Control Structure that involves executing the same number of code a number of times until a certain condition is met. The basic idea behind a loop is to automate the repetitive tasks within a program to save the time and effort. Loops in PHP are used to execute the same block of code a specified number of times. In programming it is often necessary to repeat the same block of code a given number of times, or until a certain condition is met. This can be accomplished using looping statements. • PHP supports following four loop types. • For: loops through a block of code a specified number of times. • While: loops through a block of code if and 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. • foreach: loops through a block of code for each element in an array.

  3. For Loop The for loop repeats a block of code until a certain condition is met. It is typically used to execute a block of code for certain number of times. The flowchart shown below illustrates how for loop in php works:

  4. The For-statement loop is used when you know how many times you want to execute a statement or a list of statements. For this reason, the For loop is known as a definite loop. The syntax of For loops is a bit more complex, though for loops are often more convenient than While loops. The For-loop syntax is as follows: for(initialization; condition; increment){ // Code to be executed } The parameters of for loop have following meanings: • initialization: it is used to initialize the counter variables and evaluated once unconditionally before the first execution of the body of the loop. • Condition: in the beginning of each iteration, condition is evaluated. If it evaluates to true, the loop continues and the nested statements are executed. If it evaluates to false, the execution of the loop ends. • Increment: it updates the loop counter with a new value. It is evaluate at the end of each iteration. Let’s Understand by using following Program

  5. The example below defines a loop that starts with $i=1. The loop will continue until $i is less than, or equal to 5. The variable $i will increase by 1 each time the loop runs: <html lang="en"> <head> <title>PHP for Loop</title> </head> <body> <?php for($i=1; $i<=3; $i++) { echo "The number is " . $i . "<br>"; } ?> </body> </html> Output of this code: The number is 1The number is 2The number is 3

  6. The code below uses the for loop to print values of multiplying 10 by 0 through to 10: <?php for ($i = 0; $i < 10; $i++) { $product = 10 * $i; echo "The product of 10 * $i is $product <br/>"; } ?> Output of this code: The product of 10 x 0 is 0The product of 10 x 1 is 10The product of 10 x 2 is 20The product of 10 x 3 is 30The product of 10 x 4 is 40The product of 10 x 5 is 50The product of 10 x 6 is 60The product of 10 x 7 is 70The product of 10 x 8 is 80The product of 10 x 9 is 90

  7. The following example makes five iterations and changes the assigned value of two variables on each pass of the loop: <html> <body> <?php $a = 0; $b = 0; for( $i = 0; $i<5; $i++ ) { $a += 10; $b += 5; } echo ("At the end of the loop a = $a and b = $b" ); ?> </body> </html> This will produce the following result: At the end of the loop a = 50 and b = 25

  8. While loop While loops are the simplest type of loop in PHP. The while statement will execute a block of code if and as long as a test expression is true. If the test expression is true then the code block will be executed. After the code has executed the test expression will again be evaluated and the loop will continue until the test expression is found to be false. In other words, PHP while loops allow you to execute the same piece of code continuously while a certain condition is true. Once the condition becomes false, the program will break out of the loop and continue processing the rest of the page. The flow chart shown below illustrates how Syntax: while (condition) { //Block of code to be executed; }

  9. THANK YOU CONTACT:- 70-70-90-50-90 info@ducatindia.com www.ducatindia.com

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