javascript将数组传输到新数组[重复]答案

【问题标题】：javascript transfer array to a new array [duplicate]javascript将数组传输到新数组[重复]
【发布时间】：2021-01-11 06:23:49
【问题描述】：

我目前有一个数组：

[
    {
        Id: 14,
        userRoleId: 2,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 2,
    },
    {
        Id: 15,
        userRoleId: 3,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 3,
    },
    {
        Id: 16,
        userRoleId: 4,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 3,
    },
    {
        Id: 17,
        userRoleId: 5,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 1,
    }
]

如何根据 userScopeId 生成新数组？

数组名称为userScopeArrayuserScopeId，数组内容为userScopeId匹配内容。

所以它会是这样的：

userScopeIdArray1:
[
    { Id: 17, userRoleId: 5, userResourceId: 2, userActionId: 2 }
]

userScopeIdArray2:
[
    { Id: 14, userRoleId: 2, userResourceId: 2, userActionId: 2 }
]

userScopeIdArray3:
[
    { Id: 15, userRoleId: 3, userResourceId: 2, userActionId: 2 },
    { Id: 16, userRoleId: 4, userResourceId: 2, userActionId: 2,}
]

【问题讨论】：

标签： javascript arrays

【解决方案1】：

您可以使用Array#reduce

const arr = [ { Id: 14, userRoleId: 2, userResourceId: 2, userActionId: 2, userScopeId: 2, }, { Id: 15, userRoleId: 3, userResourceId: 2, userActionId: 2, userScopeId: 3, }, { Id: 16, userRoleId: 4, userResourceId: 2, userActionId: 2, userScopeId: 3, }, { Id: 17, userRoleId: 5, userResourceId: 2, userActionId: 2, userScopeId: 1, } ];

let res = arr.reduce((acc,cur)=>{
    let id = 'userScopeId'+cur['userScopeId'];
    acc[id] = acc[id]||[];
    acc[id].push(cur);
    return acc;
},{});

console.log(res)

【讨论】：

【解决方案2】：

您可以使用reduce 数组方法来构建此结果。

let input = [
    {
        Id: 14,
        userRoleId: 2,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 2,
    },
    {
        Id: 15,
        userRoleId: 3,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 3,
    },
    {
        Id: 16,
        userRoleId: 4,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 3,
    },
    {
        Id: 17,
        userRoleId: 5,
        userResourceId: 2,
        userActionId: 2,
        userScopeId: 1,
    }
];

let output = input.reduce((acc, val) => {
  let key = "userScopeIdArray" + val.userScopeId;
  if(acc[key]){
    acc[key].push(val);
  } else{
    acc[key] = [val];
  }
  return acc;
}, {});

console.log(output);

【讨论】：