获取唯一值和重复值答案

【问题标题】：Get unique and duplicate values获取唯一值和重复值
【发布时间】：2018-03-03 20:03:35
【问题描述】：

我有这个 JSON 数据：

vm.userListData = [{
        "listId": 1,
        "permission": "READ"
    }, {
        "listId": 2,
        "permission": "WRITE"
    }, {
        "listId": 2,
        "permission": "READ"
    }, {
        "listId": 3,
        "permission": "READ"
    }, {
        "listId": 3,
        "permission": "WRITE"
    }, {
        "listId": 4,
        "permission": "WRITE"
    }, {
        "listId": 5,
        "permission": "WRITE"
    }]

还有这个：

vm.userComplementaryList = [{
    "listId": 1,
    "confidentiality": "PUBLIC",
    "listName": "List name here..1",
    "permission": "WRITE"
}, {
    "listId": 2,
    "confidentiality": "PUBLIC",
    "listName": "List name here..2",
    "permission": "READ"
}, {
    "listId": 3,
    "confidentiality": "CONFIDENTIAL",
    "listName": "List name here..3",
    "permission": "WRITE"
}, {
    "listId": 4,
    "confidentiality": "CONFIDENTIAL",
    "listName": "List name here..4",
    "permission": "WRITE"
}, {
    "listId": 5,
    "confidentiality": "CONFIDENTIAL",
    "listName": "List name here..5",
    "permission": "READ"
}]

使用这两个 JSON 数据，我必须过滤并获取唯一值并将它们推送到数组和重复的值（listId 和权限）中，将它们推送到其他数组中。我这样做了：

vm.listForGrid = [];
vm.listForDropDown = [];

(function(){
    for(var i = 0; i < vm.userComplementaryList.length; i++) { 
        for(var j = 0; j < vm.userListData.length; j++) {   
            if( (vm.userComplementaryList[i].listId == vm.userListData[j].listId) && (vm.userComplementaryList[i].permission == vm.userListData[j].permission) ) {
                vm.listForGrid.push(vm.userComplementaryList[i]);
            }
            else {
                vm.listForDropDown.push(vm.userComplementaryList[i]);
            }
        }
    }
})();

vm.listForGrid 没问题，但 vm.listForDropDown 的值不止一次，我必须 break 循环。

重复的值与两个数组中的 listId 和权限相同

谢谢！

【问题讨论】：

break 当你发现 listid 相同时。
把你的代码放到 plunkr

标签： javascript angularjs json for-loop filter

【解决方案1】：

这是一个使用 array.some 的排序器版本

vm.userComplementaryList.forEach(function(vCom) {
    vm.userListData.some(function(vUser) {
        return (vCom.listId == vUser.listId && vCom.permission == vUser.permission);
    }) ? vm.listForGrid.push(vCom) : vm.listForDropDown.push(vCom);
})

【讨论】：

【解决方案2】：

我解决了这个问题：

(function(){
    for(var i = 0; i < vm.userComplementaryList.length; i++) { 
        var found = false;
        for(var j = 0; j < vm.userListData.length; j++) {   
            if( (vm.userComplementaryList[i].listId == vm.userListData[j].listId) && (vm.userComplementaryList[i].permission == vm.userListData[j].permission) ) {
                found = true;
                break;
            }
        }
        if(found) {
            vm.listForGrid.push(vm.userComplementaryList[i]);
        }
        else {
            vm.listForDropDown.push(vm.userComplementaryList[i]);
        }
    }
})();

【讨论】：

你仍然需要一个嵌套循环来查找相同的元素。

【解决方案3】：

如果获得许可，您仍然可以使用哈希表作为参考。然后你只需要一个没有嵌套循环的循环来对项目进行排序。

var vm = {},
    permissions = {};

vm.userListData = [{ "listId": 1, "permission": "READ" }, { "listId": 2, "permission": "WRITE" }, { "listId": 2, "permission": "READ" }, { "listId": 3, "permission": "READ" }, { "listId": 3, "permission": "WRITE" }, { "listId": 4, "permission": "WRITE" }, { "listId": 5, "permission": "WRITE" }];
vm.userComplementaryList = [{ "listId": 1, "confidentiality": "PUBLIC", "listName": "List name here..1", "permission": "WRITE" }, { "listId": 2, "confidentiality": "PUBLIC", "listName": "List name here..2", "permission": "READ" }, { "listId": 3, "confidentiality": "CONFIDENTIAL", "listName": "List name here..3", "permission": "WRITE" }, { "listId": 4, "confidentiality": "CONFIDENTIAL", "listName": "List name here..4", "permission": "WRITE" }, { "listId": 5, "confidentiality": "CONFIDENTIAL", "listName": "List name here..5", "permission": "READ" }];

vm.listForDropDown = [];

vm.userListData.forEach(function (p) {
    permissions[p.listId] = permissions[p.listId] || {};
    permissions[p.listId][p.permission] = true;
});

vm.listForGrid = vm.userComplementaryList.filter(function (a) {
    if (permissions[a.listId] && permissions[a.listId][a.permission]) {
        return true;
    }
    vm.listForDropDown.push(a);
});

console.log(vm.listForGrid);
console.log(vm.listForDropDown);

.as-console-wrapper { max-height: 100% !important; top: 0; }

【讨论】：