PHP - Ds Set isEmpty() Function

The PHP Ds\Set::isEmpty() function is used to check whether the current set is empty.

It returns a boolean value 'true' if this set is empty, and false if it is not. When you print the result using the "echo" method, it will display 1 for 'true' and 0 for 'false' boolean value.

Syntax

Following is the syntax of the PHP Ds\Set::isEmpty() function −

public bool Ds\Set::isEmpty( void )

Parameters

This function does not accept any parameter.

Return value

This function returns "true" if the set is empty, or "false" otherwise.

Example 1

The following is the basic example of the PHP Ds\Set::isEmpty() function.

<?php  
   $set = new \Ds\Set();  
   echo "The set elements are: \n";
   var_dump($set);
   echo "Is set is empty? ";   
   var_dump($set->isEmpty());
?> 

Output

After executing the above program, it will return 'true'.

The set elements are:
object(Ds\Set)#1 (0) {
}
Is set is empty? bool(true)

Example 2

The following is another example of the PHP Ds\Set::isEmpty() function. We use this function to check whether this set (["Tutorials", "Point", "India"]) is empty or not.

<?php  
   $set = new \Ds\Set(["Tutorials", "Point", "India"]); 
   echo "The set elements are: \n";   
   var_dump($set);
   echo "Is set is empty? ";
   var_dump($set->isEmpty());
?>

Output

The above program returns 'false'.

The set elements are:
object(Ds\Set)#1 (3) {
  [0]=>
  string(9) "Tutorials"
  [1]=>
  string(5) "Point"
  [2]=>
  string(5) "India"
}
Is set is empty? bool(false)

Example 3

Using the isEmpty() method result within the conditional statement to check whether this set (1, 2, 3) is empty or not.

<?php  
   $set = new \Ds\Set([1, 2, 3]);  
   echo "The set elements are: \n";
   var_dump($set);
   $bool = $set->isEmpty();
   var_dump($bool);
   if($bool){
	   echo "Set is empty.";
   }
   else{
	   echo "Set is not empty";
   }
?>

Output

On executing the above program, it will generate the following output −

The set elements are:
object(Ds\Set)#1 (3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
}
bool(false)
Set is not empty