Create shortcode in WordPress, using one variable in 3 functions?

Question

I am using acfvalue variable to get value and use it in more than one shortcode, let me explain i want to store ACF value in one variable and then use that variable in 3 function and create 3 shortcode.

$acfvalue = get_field( 'short_title' );

above code is getting ACF value and storing in $acfvalue, now i want to use this variable in 3 different functions and create shortcode. i can declare and define 3 times $acfvalue and its working but i dont to fetch same value from post meta.

function hprice(){
    $acfvalue = get_field( 'short_title' );
    return '<h2>'. $acfvalue . " Price list in India" . '</h2>';
}
add_shortcode( 'pprice', 'hprice' );

function hspecs(){
    $acfvalue = get_field( 'short_title' );
    return '<h2>'. $acfvalue . " Full Specification" . '</h2>';
}
add_shortcode( 'pspecs', 'hspecs' );

function hreview(){
    $acfvalue = get_field( 'short_title' );
    return '<h2>'. $acfvalue . " Review" . '</h2>';
}
add_shortcode( 'preview', 'hreview' );

so above code is working.. problem is i want to move $acfvalue = get_field( 'short_title' ); outside of function.

Answer 1

use function to call variable

   function give_value(){
      $acfvalue = get_field( 'short_title' );
     return $acfvalue;
   }
   function hprice(){
      return '<h2>'. give_value() . " Price list in India" .'</h2>';
   }
   add_shortcode( 'pprice', 'hprice' );

   function hspecs(){
     return '<h2>'.  give_value() . " Full Specification" . '</h2>';
  }
   add_shortcode( 'pspecs', 'hspecs' );
   function hreview(){
     return '<h2>'.  give_value() . " Review" . '</h2>';
   }
   add_shortcode( 'preview', 'hreview' );

Answer 2

There are multiple ways to call get_field( 'short_title' ) only once:

Using global variable:

You can declare the $acfvalue variable global and then use it inside your function. Since global scope may have the same variable name, it's better to prefix it so that it doesn't create conflicts:

function hprice() {
    global $wpse256370_acfvalue;
    if( ! isset( $wpse256370_acfvalue ) ) {
        $wpse256370_acfvalue = get_field( 'short_title' );
    }
    return '<h2>'. $wpse256370_acfvalue . " Price list in India" . '</h2>';
}
add_shortcode( 'pprice', 'hprice' );

function hspecs() {
    global $wpse256370_acfvalue;
    if( ! isset( $wpse256370_acfvalue ) ) {
        $wpse256370_acfvalue = get_field( 'short_title' );
    }
    return '<h2>'. $wpse256370_acfvalue . " Full Specification" . '</h2>';
}
add_shortcode( 'pspecs', 'hspecs' );

function hreview() {
    global $wpse256370_acfvalue;
    if( ! isset( $wpse256370_acfvalue ) ) {
        $wpse256370_acfvalue = get_field( 'short_title' );
    }
    return '<h2>'. $wpse256370_acfvalue . " Review" . '</h2>';
}
add_shortcode( 'preview', 'hreview' );

Using static variable:

Using static variable inside a function will be better than the global variable way. Since it'll not pollute the global scope, so there is no need to prefix the variable name in this case:

function wpse256370_acfvalue() {
    static $acfvalue;
    if( ! isset( $acfvalue ) ) {
        $acfvalue = get_field( 'short_title' );
    }
    return $acfvalue;
}

function hprice() {
    return '<h2>'. wpse256370_acfvalue() . " Price list in India" . '</h2>';
}
add_shortcode( 'pprice', 'hprice' );

function hspecs() {
    return '<h2>'. wpse256370_acfvalue() . " Full Specification" . '</h2>';
}
add_shortcode( 'pspecs', 'hspecs' );

function hreview() {
    return '<h2>'. wpse256370_acfvalue() . " Review" . '</h2>';
}
add_shortcode( 'preview', 'hreview' );

Using class:

The best way is to use a class, because by using a class you also avoid possible function name conflicts:

class WPSE_256370_Shortcode {
    private static $instance;
    private $acfvalue;

    public static function init() {
        self::getInstance();
        add_shortcode( 'pprice', array( self::$instance, 'pprice' ) );
        add_shortcode( 'pspecs', array( self::$instance, 'pspecs' ) );
        add_shortcode( 'preview', array( self::$instance, 'preview' ) );
    }

    public static function getInstance() {
        if( ! isset( self::$instance ) ) {
            self::$instance = new self;
        }
        return self::$instance;     
    }

    public function acfvalue() {
        if( ! isset( $this->acfvalue ) ) {
            $this->acfvalue = get_field( 'short_title' );
        }
        return $this->acfvalue;
    }

    public function pprice() {
        return '<h2>'. $this->acfvalue() . " Price list in India" . '</h2>';
    }

    public function pspecs() {
        return '<h2>'. $this->acfvalue() . " Full Specification" . '</h2>';
    }

    public function preview() {
        return '<h2>'. $this->acfvalue() . " Review" . '</h2>';
    }
}
WPSE_256370_Shortcode::init();