advanced search engine system
function search($name, $age, $country, $job) { // do something } search('John', 20, 'US', 'Programmer'); // another day search('John', 20, 'US', 'Programmer', 'male'); // another day search('John', 20, 'US', 'Programmer', 'male', 'single'); // another day search('John', 20, 'US', 'Programmer', 'male', 'single', 'love cats'); // another day search('John', 20, 'US', 'Programmer', 'male', 'single', 'love cats', 'xxx'); // another day search('John', 20, 'US', 'Programmer', 'male', 'single', 'love cats', 'xxx', 'yyy');