const?createStore?=?(reducer)?=>?{ ??let?state; ??let?listeners?=?[]; ??const?getState?=?()?=>?state;//這里的箭頭函數轉換成一般的函數是這樣的嗎？const?getState=function(){return?state;} ??const?dispatch?=?(action)?=>?{ ????state?=?reducer(state,?action); ????listeners.forEach(listener?=>?listener());//這部分代碼是什么意思，箭頭函數怎么轉換？ ??}; ??const?subscribe?=?(listener)?=>?{ ????listeners.push(listener); ????return?()?=>?{ ??????listeners?=?listeners.filter(l?=>?l?!==?listener);//想問下這里的箭頭函數轉換成一般的函數是什么樣的？listeners.filter是什么意思 ????} ??}; ??dispatch({}); ??return?{?getState,?dispatch,?subscribe?};};