javascript - 使用Lodash合并数组，为什么结果重复数组值？，我的代码哪里错了？

Question

我的代码

var result = [];

var datax = [{
    "tag": "TH000144"
}, {
    "tag": "TH000147"
}, {
    "tag": "TH000166"
}, {
    "tag": "TH000169"
}, {
    "tag": "TH000170"
}];

var newdatax = [{
    "serial": "14563",
    "tag": "TH000144"
}, {
    "serial": "7777",
    "tag": "TH000147"
}, {
    "tag": "TH000169",
    "serial": null
}];

var result = lodash.merge(datax, newdatax);

结果

[{
    "tag": "TH000144",
    "serial": "14563"
}, {
    "tag": "TH000147",
    "serial": "7777"
}, {
    "tag": "TH000169",
    "serial": null
}, {
    "tag": "TH000169"
}, {
    "tag": "TH000170"
}]

我需要这样

[{
    "tag": "TH000144",
    "serial": "14563"
}, {
    "tag": "TH000147",
    "serial": "7777"
}, {
    "tag": "TH000169",
    "serial": null
}, {
    "tag": "TH000166"
}, {
    "tag": "TH000170"
}]

我的代码哪里错了？

Answer 1

反转合并的参数，如_.merge(newdatax, datax);

我对问题的看法:

当递归合并函数到达TH000169时，它解析为未定义；似乎很可能是由于序列号的 null 值所致。文档提到了这个潜在的挂断 HERE 。该文档还建议它应采用 _.merge(destination, source); 的形式。

var result = [];

var datax = [{
    "tag": "TH000144"
}, {
    "tag": "TH000147"
}, {
    "tag": "TH000166"
}, {
    "tag": "TH000169"
}, {
    "tag": "TH000170"
}];

var newdatax = [{
    "serial": "14563",
    "tag": "TH000144"
}, {
    "serial": "7777",
    "tag": "TH000147"
}, {
    "tag": "TH000169",
    "serial": null
}];

var result = _.merge(newdatax, datax);
console.log(JSON.stringify(result, null, 4));

结果

[
    {
        "serial": "14563",
        "tag": "TH000144"
    },
    {
        "serial": "7777",
        "tag": "TH000147"
    },
    {
        "tag": "TH000166",
        "serial": null
    },
    {
        "tag": "TH000169"
    },
    {
        "tag": "TH000170"
    }
]