How to filter a JS array with user defined number of filters?-CodePudding

I have a Profiles array of objects that I would like to filter. The filter is a combination of Statuses in another array. The array of Statuses is defined by the user. The Profiles array can be filtered with one or more Statuses by the user. How can I write a filter function without knowing how many conditions should be checked in advance?

//the array to filter
let profileList = [{name: "John", staus: "green"}, {name: "Alex", staus: "yellow"}, {name: "Jane", staus: "green"}]

//user defined: they can add up to 30 statuses
let statusList = ["green", "yellow", "red", "black"]

//also user defined: they can filter by as many statuses as they want
let filters = ["green", "red"]

  
const filteredProfileList = profileList.filter(element => {
  return //how to write the conditions with logical OR (||) if I don't know how many statuses will be used?
});

CodePudding user response：

You don't need to know how many will be checked, you can just check if the array of filters includes the profiles status:

//the array to filter
let profileList = [{name: "John", staus: "green"}, {name: "Alex", staus: "yellow"}, {name: "Jane", staus: "green"}]

//user defined: they can add up to 30 statuses
let statusList = ["green", "yellow", "red", "black"]

//also user defined: they can filter by as many statuses as they want
let filters = ["green", "red"]

  
const filteredProfileList = profileList.filter(element => {
  return filters.includes(element.staus);
});

console.log(filteredProfileList)

CodePudding user response：

To filter a JavaScript array with a user-defined number of filters, you can use the Array.prototype.filter() method in combination with the Function.prototype.apply() method. The filter() method allows you to specify a callback function that will be used to test each element in the array, and the apply() method allows you to apply the callback function to the array with a variable number of arguments.

Here is an example of how this can be done:

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

// Define the filter callback function
function filterFunc(value) {
  // Get the arguments passed to the apply() method
  const args = [].slice.call(arguments, 1);

  // Iterate over the arguments and return false if the value is not in the list
  for (let i = 0; i < args.length; i  ) {
    if (value === args[i]) {
      return false;
    }
  }

  // Return true if the value is not in the list of arguments
  return true;
}

// Filter the array with the user-defined number of filters
const result = numbers.filter(function() {
  // Apply the filter callback function to the array with the arguments passed to this function
  return filterFunc.apply(this, arguments);
}, 1, 3, 5, 7, 9);

// Output the filtered array
console.log(result); // [2, 4, 6, 8, 10]

In the example above, the filterFunc function is defined as the callback function for the filter() method. The filterFunc function takes a single value as its argument and returns true if the value is not in the list of arguments passed to the apply() method. The apply() method is then called with the filterFunc function and the list of arguments provided by the user. This causes the filterFunc function to be applied to each element in the numbers array with the user-defined filters, and the resulting array is returned by the filter() method.

You can adjust the code as needed to suit your specific needs, such as using different callback functions or providing different arguments to the apply() method.