javascript - 创建 javascript 递归过滤器函数

Question

有什么方法可以使这个函数递归，这样我就不需要为过滤条件的每个长度创建一个开关？

var data = [
  {a:'aaa',b:'bbb',c:'ccc',d:'ddd',e:'eee'},
  {a:'aaa',b:'bbb',c:'ccc',d:'eee',e:'fff'},
  {a:'xxx',b:'bbb',c:'ccc',d:'ddd',e:'fff'}
]


function select(data,where){
  return data.filter(function(e){ 
    var k = Object.keys(where); 
    switch(k.length){     
      case 1: return (e[k[0]] == where[k[0]]);
      case 2: return (e[k[0]] == where[k[0]] && e[k[1]] == where[k[1]]);
      case 3: return (e[k[0]] == where[k[0]] && e[k[1]] == where[k[1]] && e[k[2]] == where[k[2]]);
      case 4: return (e[k[0]] == where[k[0]] && e[k[1]] == where[k[1]] && e[k[2]] == where[k[2]] && e[k[3]] == where[k[3]]);
      case 5: return (e[k[0]] == where[k[0]] && e[k[1]] == where[k[1]] && e[k[2]] == where[k[2]] && e[k[3]] == where[k[3]] && e[k[4]] == where[k[4]]);
    }
  })  
}

var where = {a:'aaa',b:'bbb'}

console.log(select(data,where));

Answer 1

它不需要递归(我不确定你明白这意味着什么)，你只需要循环 where 中的元素即可:

function select(data, where) {
  return data.filter(function(e) {
    var k = Object.keys(where);
    return k.every(function(key) {
      return e[key] == where[key];
    });
  })
}

var data = [
  {a:'aaa',b:'bbb',c:'ccc',d:'ddd',e:'eee'},
  {a:'aaa',b:'bbb',c:'ccc',d:'eee',e:'fff'},
  {a:'xxx',b:'bbb',c:'ccc',d:'ddd',e:'fff'}
]

var where = {a:'aaa',b:'bbb'}

console.log(select(data,where));