The Ds\Stack::isEmpty() function of PHP Ds\Stack class is used to check whether a Stack is empty or not. This method returns a boolean value, True if the Stack is empty otherwise it returns False.
Syntax:
bool public Ds\Stack::isEmpty ( void )
Parameter: This function does not accept any parameters.
Return Value: This function returns a boolean value True if the stack is Empty otherwise it returns False.
Below programs illustrate the Ds\Stack::isEmpty() function:
Program 1:
PHP
<?php // PHP program to illustrate the // Ds\stack::isEmpty() function // Create a Stack instance $stack = new \Ds\Stack();
// Check if stack is Empty var_dump( $stack ->isEmpty());
// Pushing elements to Stack $stack ->push( "Welcome" );
$stack ->push( "to" );
$stack ->push( "GfG" );
// Check if stack is Empty again var_dump( $stack ->isEmpty());
?> |
Output:
bool(true) bool(false)
Program 2:
PHP
<?php // PHP program to illustrate the // Ds\stack::isEmpty() function // Create a Stack instance $stack = new \Ds\Stack();
// Check if stack is Empty var_dump( $stack ->isEmpty());
// Pushing Mixed value elements to Stack $stack ->push( "Welcome" );
$stack ->push( "to" );
$stack ->push( "GfG" );
$stack ->push(10);
$stack ->push(5.5);
// Check if stack is Empty again var_dump( $stack ->isEmpty());
?> |
Output:
bool(true) bool(false)
Reference: http://php.net/manual/en/ds-stack.isempty.php