PHP105

PHP105 - Expressions, Operators, and Variable Assignments

Exercise 1

Type the following code as part of a web page. Experiment with changing values and operations until you fully understand how to manipulate variables in this exercise.

<?
   $num = 1
   echo 'num is now: $num<BR>';
   $num = 4 + 9;
   echo 'num is now: $num<BR>';
   /*
   ** all the following add one to the value of $num
   */
   $num = $num + 1;
   echo 'num is now: $num<BR>';
   $num += 1;
   echo 'num is now: $num<BR>';
   $num++;
   echo 'num is now: $num<BR>';
   /*
   ** these subtract one from $num
   */
   $num = $num -1;
   echo 'num is now: $num<BR>';
   $num -= 1;
   echo 'num is now: $num<BR>';
   $num--;
   echo 'num is now: $num<BR>';
   /*
   ** double the value of $num
   */
   $num = 23;
   echo 'num is now: $num<BR>';
   $num = $num * 2;
   echo 'num is now: $num<BR>';
   $num *= 2;
   echo 'num is now: $num<BR>';
   /*
   ** halve the value of $num
   */
   $num = 100;
   echo 'num is now: $num<BR>';
   $num = $num / 2;
   echo 'num is now: $num<BR>';
   $num /= 2;
   echo 'num is now: $num<BR>';
   /*
   ** A combination 
   */
   $num = 8;
   echo 'num is now: $num<BR>';
   $num = (((($num + 4) * 2)  - 6) / 3);
   echo 'num is now: $num<BR>';
 ?>