Array variables allow us to group related PHP data values together in a list using a single variable name. We can store multiple data in a single variable.

1. Define variable or variable assignment

Let us define separate variable for storing data of students , teachers and staff

              <?php 

              $name="manoj";
              $age=20;
              $dob="20-01-2020";
              $english=50;
              $malayalam=50;
              $computer=50;
              $maths=50;
              $gk=50;



              $teachers_name="manoj";
              $teachers_age=20;
              $teachers_dob="20-01-2020";
              $basic=25000;
              $hra=5000;
              $ta=100;



              $staff_name="manoj";
              $staff_age=20;
              $staff_dob="20-01-2020";
              $staff_basic=25000;
              $staff_hra=5000;
              $staff_ta=100;


             

              ?>

            

The above method is not good for managing or maintaining the variables while developing an application

2. Group the related data and store in a single variable using array

Syntax

                $variable_name = [];

                OR

                $variable_name = ['key' => 'value'];

            

1. $ sign must be in front of the variable name
2. = sign for assigning the value to a variable
3. => sign for separating key and value in an array
4. , sign for separating the multiple values in an array

              <?php 

              $student=["name" => "manoj", "age" => 20, "dob" => "20-01-2020", "english" => 50, "malayalam" => 60, "computer" => 70, "maths" => 80, "gk" => 90];     
              
              // OR    
              $student["name"]="manoj";
              $student["age"]=20;   


              $teacher=["name" => "manoj",  "age" => 20, "dob" => "20-01-2020", "basic" => 25000, "hra" => 5000, "ta" => 100]; 
              
              // OR 
              $teacher["name"]="manoj";
              $teacher["age"]=20;



              $staff=["name" => "manoj", "age" => 20, "dob" => "20-01-2020", "basic" => 25000, "hra" => 5000, "ta" => 100];

              // OR 
              $staff["name"]="manoj";
              $staff["age"]=20;

              ?>

            

3. Read the array data with key

              <?php 

              $student["name"];   
              $student["age"];  
              $student["dob"];         

              $teacher["name"]; 
              $teacher["age"]; 
              $teacher["dob"]; 

              $staff["name"];
              $staff["age"];
              $staff["dob"];

              ?>

            

4. update array data with key

              <?php 

              $student["name"]="manoj1";   
              $student["age"]=25;  
              $student["dob"]="20-01-2020"; 
              
              
              $teacher["name"]="manoj1";   
              $teacher["age"]=25;  
              $teacher["dob"]="20-01-2020";      

        
              ?>

            

5. output to the browser using echo

            <?php 

           echo  $student["name"];   
           echo $student["age"];  
           echo $student["dob"];         

           echo  $teacher["name"]; 
           echo  $teacher["age"]; 
           echo  $teacher["dob"]; 

           echo $staff["name"];
           echo  $staff["age"];
           echo  $staff["dob"];

            ?>

          

6. Show the data user friendly

                <table>
                    <tr>
                        <td>Student Name</td>
                        <td> 
                            <?php                              
                              echo  $student["name"]; 
                            ?>
                        </td>
                  </tr>

                  <tr>
                        <td>Student Age</td>
                        <td> 
                            <?php                              
                              echo  $student["age"]; 
                            ?>
                        </td>
                  </tr>

                  <tr>
                        <td>Student DOB</td>
                        <td> 
                            <?php                              
                              echo $student["dob"]; 
                            ?>
                        </td>
                  </tr>



                </table>



                <table>
                    <tr>
                        <td>Teacher Name</td>
                        <td> 
                            <?php                              
                              echo  $teacher["name"]; 
                            ?>
                        </td>
                  </tr>

                  <tr>
                        <td>Teacher Age</td>
                        <td> 
                            <?php                              
                              echo  $teacher["age"]; 
                            ?>
                        </td>
                  </tr>

                  <tr>
                        <td>Teacher DOB</td>
                        <td> 
                            <?php                              
                              echo $teacher["dob"]; 
                            ?>
                        </td>
                  </tr>



                </table>




                <table>
                    <tr>
                        <td>Staff Name</td>
                        <td> 
                            <?php                              
                              echo  $staff["name"]; 
                            ?>
                        </td>
                  </tr>

                  <tr>
                        <td>Staff Age</td>
                        <td> 
                            <?php                              
                              echo  $staff["age"]; 
                            ?>
                        </td>
                  </tr>

                  <tr>
                        <td>Staff DOB</td>
                        <td> 
                            <?php                              
                              echo $staff["dob"]; 
                            ?>
                        </td>
                  </tr>



                </table>