Php problem $ market

$ Shop_price! Empty ($ _ POST [shop_price])? $ _ POST [shop_price] * 0.9: 0; $ market_price! Empty ($ _ POST [market_price])? $ _ POST [market_price]: round ($ shop_price * $ GLOBALS [_ CFG] [market_price_rate]); $ zmm_tejiaexplode (, $ _

// $ Shop_price =! Empty ($ _ POST ['shop _ price'])? $ _ POST ['shop _ price'] * 0.9: 0; // $ market_price =! Empty ($ _ POST ['market _ price'])? $ _ POST ['market _ price']: round ($ shop_price * $ GLOBALS ['_ CFG'] ['market _ price_rate']); $ zmm_tejia = explode ('', $ _

// $ Shop_price =! Empty ($ _ POST ['shop _ price'])? $ _ POST ['shop _ price'] * 0.9: 0;
// $ Market_price =! Empty ($ _ POST ['market _ price'])? $ _ POST ['market _ price']: round ($ shop_price * $ GLOBALS ['_ CFG'] ['market _ price_rate']);

$ Zmm_tejia = explode ('', $ _ POST [cn_goods_name]);

What do these functions mean? In particular, $ market_price =! Empty ($ _ POST ['market _ price'])? $ _ POST ['market _ price']: round ($ shop_price * $ GLOBALS ['_ CFG'] ['market _ price_rate']);