在javascript中获取矩阵的所有可能选项

Question

我在JavaScript中有一个'item'对象,该项可以有颜色,大小等设置.

我需要在数组中获得所有可能的组合.

所以我们假设我们有一个看起来像这样的项目:

var newItem = {
    name: 'new item',
    Settings: [
        {name: 'color', values: ['green', 'blue', 'red']},
        {name: 'size',  values: ['15', '18', '22']},
        {name: 'gender',values: ['male', 'female']}
    ]
};

我需要以某种方式得到这个:

[
    [{SettingName:'color',value:'green'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'blue'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'red'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'green'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'blue'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'red'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'green'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'blue'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'red'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'male'}],
    [{SettingName:'color',value:'green'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'blue'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'red'},{SettingName:'size',value:'15'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'green'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'blue'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'red'},{SettingName:'size',value:'18'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'green'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'blue'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'female'}],
    [{SettingName:'color',value:'red'},{SettingName:'size',value:'22'},{SettingName:'gender',value:'female'}]
]

Answer 1

这可能是一个很好的面试问题.
有关运行示例,请参阅JS Bin.

getAllPermutations(newItem);

function getAllPermutations(item) {
    var permutations = [];

    getAllPermutations0(item, permutations, []);
    console.log(permutations);
}

function getAllPermutations0(item, permutations, array) {
    if (array && array.length === item.Settings.length) {
        permutations.push(array.slice()); // The slice clone the array
        return;
    }

    var index =  array.length;
    var setting = item.Settings[index];

    for (var i = 0; i < setting.values.length; i++) {
        if (index === 0)
            array =  [];

        var currValue = setting.values[i];

        array.push({
            SettingName: setting.name,
            value: currValue
        });

        getAllPermutations0(item, permutations, array);
        array.pop(); // pop the old one first
    }
}