如何在javascript中从数组中删除x或y以外的元素

Question

I am trying to remove all the elements from the array other then x or y (if available)

Example: Case 1:

let array = ['a','b','c','d','x','y']

So,in that case, other then x and y, I want to remove all the other elements. output: ['x','y']

Case 2:

let array = ['a','b','c','d','x']

In this case, other then x, I want to remove all the other elements. output: ['x']

Case 3:

let array = ['a','b','c','d']

In this case, I want to remove all the elements. output: [ ]

Couldn't find a better approach to go ahead with that. Any help will be appreciated. THANK YOU :)

Answer 1

Simply declare the allowed strings in inside an alone array and then use the filter method on the array.

const allowedStrings = ['x', 'y'];

let array = ['a','b','c','d','x','y'].filter(
   item => allowedStrings.includes(item)
);`

Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

Answer 2

You can use Array.filter and Array.includes .

let array = ['a','b','c','d','x','y'].filter(item => ['x','y'].includes(item));
console.log(array);

Answer 3

您可以使用以下命令完成此操作：

array = array.filter(v => v==="x" || v==="y")

Answer 4

You can accomplish this with Array.prototype.filter() and Array.prototype.includes

 let array = ['a', 'b', 'c', 'd']; // create the array // filter out every letter not included in the given array console.log(array.filter((letter) => ['a', 'b'].includes(letter))); // you can also filter out every letter that *is* is the given array console.log(array.filter((letter) => !['a', 'b'].includes(letter)));