php: helperfunctions

gistfile1

<?php
class HelperFunctions
{
	/**
	 * This function is responsible to convert % to double
	 * @param integer $a 
	 * @return double
	 */
	public static function isPercentage($a){
		if(preg_match('/%/',$a)){
			$e=explode('%', $a);
			return $e[0]/100;
		}else{
			return $a;
		}    	
	}
	/**
	 * This function to var_dump replica
	 * @param array $value 
	 * @return array
	 */
	public static function dump($value){
		$out = "<pre>";
		$out.= var_dump($value);
		$out.= "</pre>";
		return $out;
	}
	/**
	 * This function responsible to rid of whitespaces and replace with dash
	 * @param string $string 
	 * @return string
	 */
	public static function fetch_value($string){    
        $string = trim($string);
        $string = mysql_real_escape_string($string);
        $string = stripslashes($string);
        $string = preg_replace('/[ _]+/', '-', $string);
        return $string;
	}
	/**
	 * This is useful to get the dates
	 * @return array
	 */
	public static function dateRange()
	{
		$date = isset($_GET['date']) ? $_GET['date'] : date('Y-m-d');
		$previous_date = date('Y-m-d', strtotime($date .' -1 day'));
		$next_date = date('Y-m-d', strtotime($date .' +1 day'));
		return array('<a href="?date='.$previous_date.'">Previous</a>','<a href="?date='.$next_date.'">Next</a>');
	}
	/**
	 * This will return previous and next dates
	 * @return string
	 */
	public static function datePrevious()
	{
		$arr = list($previous_date,$next_date) = HelperFunctions::dateRange();
		return $arr;
	}

}
echo (HelperFunctions::datePrevious()[0]);
echo (HelperFunctions::datePrevious()[1]);