以下语句在JS中做什么

Question

I am new to JS with react+redux framework and I have a code that as follows in reducer code.

export const operationState = (state = someState, action = {}) => {
    //some case handler 
}

Please help me in understanding what will this translates to.

Answer 1

它导出一个带有参数state和action的名为operationState的函数，如果您在调用operationState()时未传递任何内容，则默认为someState和{}