通过检查多个条件来筛选Javascript数组

Question

我有一个数组：

var arr = 
[
    {
        "id":3,
        "first_name":"Laila",
        "last_name":"McCaine",
        "gender":"female",      
        "populations":[{"population_name":"Heart failure"}, {"population_name":"AMI"}],
        "score": 55.0
    },
    {
        "id":5,     
        "first_name":"Riva",
        "last_name":"Rontgen",
        "gender":"female",
        "populations":[{"population_name":"Pnumonia"}],
        "score": 85.0
    },
    {
        "id":8,
        "first_name":"Emily",   
        "last_name":"Rosewood",
        "gender":"female",  
        "populations":[],
        "score": 25.0
    }
];

变量：

var score='';
var population='';
var status = '';

我想使用数组的 filter 函数，并使用 and 条件，例如获取得分小于40、状态为1且人口名称为“心力衰竭”的记录。

问题在于，给定的三个变量是 dynamic 的，如果它们的值为 ''，则不应用 filter。

我该如何实现这一点？

- Dev

---

你想要在数组每次被修改时自动应用数组过滤器吗？ - Redu

很简单，检查过滤器是否为 ""；你尝试了什么？ - T.J. Crowder

Answer 1

像这样的：

arr.filter(function(item) {
    var ok = true;

    if (score !== '') {
        ok = item.score < score;
    }

    if (ok && population !== '') {
        // check it
        ok = item.populations.map(function() {return item.population_name;}).indexOf(population) > -1;
    }

    if (ok && status !== '') {
        // check status
    }

    return ok;
});

- Evan Trimboli

Answer 2

var arr = 
[
    {
        "id":3,
        "status": 1,
        "first_name":"Laila",
        "last_name":"McCaine",
        "gender":"female",      
        "populations":[{"population_name":"Heart failure"}, {"population_name":"AMI"}],
        "score": 55.0
    },
    {
        "id":5,   
        "status": 1,
        "first_name":"Riva",
        "last_name":"Rontgen",
        "gender":"female",
        "populations":[{"population_name":"Pnumonia"}],
        "score": 85.0
    },
    {
        "id":8,
        "status": 0,
        "first_name":"Emily",   
        "last_name":"Rosewood",
        "gender":"female",  
        "populations":[],
        "score": 25.0
    }
];

function filterRecords( arr ){
  return arr.filter(function( record ){
    return record.score > 40 && record.status && (record.populations.filter(function( population ){
      return population.population_name == 'Heart failure';
    })).length;
  });
}

console.log( filterRecords( arr ) );

<script src="http://codepen.io/synthet1c/pen/WrQapG.js"></script>

- synthet1c