如何在嵌套的 javascript 对象上使用扩展运算符?
How to use spread operator on nested javascript objects?
我正在尝试更新我的部分 redux 状态,其中包含嵌套在另一个对象中的两个对象。通常在不可变地更新 javascript 对象时,我会使用扩展运算符,然后按如下方式定义任何更改:
state = {...state, property1: newvalue}
但是,当我有嵌套对象时,我不确定如何使用扩展运算符。这是相关代码和我的尝试:
const squadDatabase = {currentSquad: {
0: null,
1: null,
2:null
}, newAdditions: null}
export default (state=initial_squad, action)=>{
switch(action.type){
case ADD_PLAYER_TO_SQUAD:
return {...state, currentSquad[action.payload.currentSquadMemberId]:action.payload.newSquadAdditionId, newAdditions: action.payload.newSquadAdditionId}
default:
return initial_squad
}
}
有谁知道如何使用扩展运算符或其他方式不可变地更新嵌套的 javascript 对象?
基本上你必须添加第二级对象(状态)解构。
return {
...state, // first nesting level spread
currentSquad: {
...this.state.currentSquad, // second nesting level spread
currentSquad[action.payload.currentSquadMemberId]: action.payload.newSquadAdditionId,
},
newAdditions: action.payload.newSquadAdditionId,
};
我正在尝试更新我的部分 redux 状态,其中包含嵌套在另一个对象中的两个对象。通常在不可变地更新 javascript 对象时,我会使用扩展运算符,然后按如下方式定义任何更改:
state = {...state, property1: newvalue}
但是,当我有嵌套对象时,我不确定如何使用扩展运算符。这是相关代码和我的尝试:
const squadDatabase = {currentSquad: {
0: null,
1: null,
2:null
}, newAdditions: null}
export default (state=initial_squad, action)=>{
switch(action.type){
case ADD_PLAYER_TO_SQUAD:
return {...state, currentSquad[action.payload.currentSquadMemberId]:action.payload.newSquadAdditionId, newAdditions: action.payload.newSquadAdditionId}
default:
return initial_squad
}
}
有谁知道如何使用扩展运算符或其他方式不可变地更新嵌套的 javascript 对象?
基本上你必须添加第二级对象(状态)解构。
return {
...state, // first nesting level spread
currentSquad: {
...this.state.currentSquad, // second nesting level spread
currentSquad[action.payload.currentSquadMemberId]: action.payload.newSquadAdditionId,
},
newAdditions: action.payload.newSquadAdditionId,
};