如何过滤和循环遍历JavaScript中的嵌套关​​联对象？

Question

So I have three nested associative objects/arrays in total. Employee1 and employee2 were first made, and then employees was created in order to nest the two associative objects. Next, I created a third associative object, employee3, to nest into the employees object. What I am trying to do now is filter through the 2D array using the .filter() method to only bring up the employees that are currently working there, which is indicated in the arrays by ["isCurrent"] = true; but all I'm getting in the console window is undefined. Why is this happening and how do I fix this?

 var employee1 = []; employee1["id"] = 33; employee1["name"] = "Carey Shanks"; employee1["title"] = "Knife Maker"; employee1["department"] = "fabrication"; employee1["isCurrent"] = true; var employee2 = []; employee2["id"] = 34; employee2["name"] = "Giles Newman"; employee2["title"] = "Lead Sales"; employee2["department"] = "Customer Service"; employee2["isCurrent"] = true; var employees = []; employees[0] = []; employees[0]["id"] = 33; employees[0]["name"] = "Carey Shanks"; employees[0]["title"] = "Knife Maker"; employees[0]["department"] = "fabrication"; employees[0]["isCurrent"] = true; var employee3 = []; employee3["id"] = 35; employee3["name"] = "Tori G."; employee3["title"] = "Product Demonstrator"; employee3["department"] = "Marketing"; employee3["isCurrent"] = false; //MERING THE ARRAYS employees.push(employee2); employees.push(employee3); //TESTING TO SEE IF IT POPULATED //window.console.log(employees); var i; var currentEmployee = function (isCurrent) { var isCurrentEmployee = true; for (i in employees) { if (isCurrent !== true) { isCurrentEmployee = false; break; } } return isCurrentEmployee; }; var isCompanyEmployee = employees.filter(currentEmployee); window.console.log(isCompanyEmployee[i]); 

Answer 1

Some issues:

• Arrays should only be used with numeric indicies. If you want to use arbitrary string keys, use an object instead.

• The first argument to the filter callback is the current item being iterated over; your

   var currentEmployee = function (isCurrent) { 

  defines isCurrent as the first argument, but that's not the isCurrent property. If you wanted to immediately extract the isCurrent property from the object, destructure the parameter instead, and then you can just return it:

   var currentEmployee = function ({ isCurrent }) { return isCurrent; } 

  Or, if you're not comfortable with destructuring, this is equivalent to

   var currentEmployee = function (employee) { return employee.isCurrent; } 

• i has no meaning outside the currentEmployee function - log the filtered array instead:

   console.log(isCompanyEmployee); 

• You never push employee1 to the array.

 var employee1 = {}; employee1["id"] = 33; employee1["name"] = "Carey Shanks"; employee1["title"] = "Knife Maker"; employee1["department"] = "fabrication"; employee1["isCurrent"] = true; var employee2 = {}; employee2["id"] = 34; employee2["name"] = "Giles Newman"; employee2["title"] = "Lead Sales"; employee2["department"] = "Customer Service"; employee2["isCurrent"] = true; var employees = []; employees[0] = {}; employees[0]["id"] = 33; employees[0]["name"] = "Carey Shanks"; employees[0]["title"] = "Knife Maker"; employees[0]["department"] = "fabrication"; employees[0]["isCurrent"] = true; var employee3 = {}; employee3["id"] = 35; employee3["name"] = "Tori G."; employee3["title"] = "Product Demonstrator"; employee3["department"] = "Marketing"; employee3["isCurrent"] = false; //MERING THE ARRAYS employees.push(employee1); employees.push(employee2); employees.push(employee3); //TESTING TO SEE IF IT POPULATED //window.console.log(employees); var i; var currentEmployee = function ({ isCurrent }) { return isCurrent; }; var currentEmployees = employees.filter(currentEmployee); window.console.log(currentEmployees);