Online PHP editor | output for n4SMB

<?php $js = "Morris.Donut({ element: 'piechart', data: [ {label: 'Option 1', value: ${op1}$ }, {label: 'Option 2', value: ${op2}$ }, {label: 'Option 3', value: ${op3}$ }, {label: 'Option 4', value: ${op4}$ } ], colors: [\"#3228db\", \"#34225e\", \"#1abc3c\", \"#24495e\", \"#9b51b6\", \"#15a5a6\"], formatter: function (y) { return y + \"%\" } });"; $op1 = 25; $op2 = 40; $op3 = 25; $op4 = 10; $matches = array(); $vars = array(); $i=0; while(preg_match("/\$\{([^\}]*)\}\$/", $js, &$matches)){ $vars[$i++] = $matches[1]; } print_r($vars);