How to delete an array element based on key in PHP?

To delete an array element based on a key in PHP, the code is as follows−

Example

 Live Demo

<?php
   $arr = array( " John ", "Jacob ", " Tom ", " Tim ");
   echo "Array with leading and trailing whitespaces...
";
   foreach( $arr as $value ) {
      echo "Value = $value 
";
   }
   echo "
Comma separated list...
";
   print_r(implode(', ', $arr));
   $result = array_map('trim', $arr);
   echo "
Updated Array...
";
   foreach( $result as $value ) {
      echo "Value = $value 
";
   }
   unset($result[1]);
   echo "
Updated Array...
";
   foreach( $result as $value ) {
      echo "Value = $value 
";
   }
?>

Output

This will produce the following output−

Array with leading and trailing whitespaces...
Value = John
Value = Jacob
Value = Tom
Value = Tim
Comma separated list...
John , Jacob , Tom , Tim
Updated Array...
Value = John
Value = Jacob
Value = Tom
Value = Tim
Updated Array...
Value = John
Value = Tom
Value = Tim

Example

Let us now see another example −

 Live Demo

<?php
   $marks = array(
      "kevin" => array (
         "physics" => 95,
         "maths" => 90,
      ),
      "ryan" => array (
         "physics" => 92,
         "maths" => 97,
      ),
   );
   echo "Marks for kevin in physics : " ;
   echo $marks['kevin']['physics'] . "
";
   echo "Marks for ryan in maths : ";
   echo $marks['ryan']['maths'] . "
";
   unset($marks["ryan"]);
   echo "Marks for ryan in maths : ";
   echo $marks['ryan']['maths'] . "
";
?>

Output

This will produce the following output. Now, an error would be visible since we deleted the element and trying to access it−

Marks for kevin in physics : 95
Marks for ryan in maths : 97
Marks for ryan in maths :
PHP Notice: Undefined index: ryan in /home/cg/root/6985034/main.php on line 25