Wednesday 15 January 2014

A complete PHP Tutorial For Beginners To Learn PHP Basic Part 7


  • PHP Looping


    • The while Loop

      • Syntax

        1. while (condition) 
        2. code to be executed; 
        3. }
        • Example

          • The example below defines a loop that starts with i=1. The loop will continue to run as long as i is less than, or equal to 5. i will increase by 1 each time the loop runs:
          1. <html> 
          2. <body> 
          3. <?php 
          4. $i=1; while($i<=5) 
          5. echo "The number is " . $i . "<br />"; 
          6. $i++; 
          7. ?> 
          8. </body> 
          9. </html>
          • Output:

          1. The number is 1 
          2. The number is 2 
          3. The number is 3 
          4. The number is 4 
          5. The number is 5
      • The do...while Statement


        • The do...while statement will always execute the block of code once, it will then check the condition, and repeat the loop while the condition is true.
        • Syntax

          1. do 
          2. code to be executed; 
          3. while (condition);
          • Example

            • The example below defines a loop that starts with i=1. It will then increment i with 1, and write some output. Then the condition is checked, and the loop will continue to run as long as i is less than, or equal to 5:
            1. <html> 
            1. <body> 
            2. <?php 
            3. $i=1; 
            4. do 
            5. $i++; 
            6. echo "The number is " . $i . "<br />";
            7. while ($i<=5); 
            8. ?> 
            9. </body> 
            10. </html>
            • Output:
            1. The number is 2 
            2. The number is 3 
            3. The number is 4 
            4. The number is 5 
            5. The number is 6

            • The for Loop

              • Syntax

                1. for (init; condition; increment) 
                2. code to be executed; 
                3. }
              • Parameters
              • init: Mostly used to set a counter (but can be any code to be executed once at the beginning of the loop)
              • condition: Evaluated for each loop iteration. If it evaluates to TRUE, the loop continues. If it evaluates to FALSE, the loop ends.
              • increment: Mostly used to increment a counter (but can be any code to be executed at the end of the loop)
            • Example

              • The example below defines a loop that starts with i=1. The loop will continue to run as long as i is less than, or equal to 5. i will increase by 1 each time the loop runs:
              1. <html> 
              2. <body> 
              3. <?php 
              4. for ($i=1; $i<=5; $i++) 
              5. echo "The number is " . $i . "<br />"; 
              6. } ?> 
              7. </body> 
              8. </html>
              • Output:

              1. The number is 1 
              2. The number is 2 
              3. The number is 3 
              4. The number is 4 
              5. The number is 5
          • The foreach Loop

            • Syntax

              1. foreach ($array as $value) 
              2. code to be executed; 
              3. }
              • For every loop iteration, the value of the current array element is assigned to $value (and the array pointer is moved by one) - so on the next loop iteration, you'll be looking at the next array value.
              • Example

                • The following example demonstrates a loop that will print the values of the given array:
                1. <html> 
                2. <body> 
                3. <?php 
                4. $x=array("one","two","three"); 
                5. foreach ($x as $value) 
                6. echo $value . "<br />"; 
                7. ?> 
                8. </body> 
                9. </html>
                • Output:

                1. one 
                2. two 
                3. three


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