How to get the difference of two string arrays?

Question

I want to get the exact difference between two string arrays.

const array1 = [\'T\',\'E\',\'A\',\'P\',\'A\',\'P\',\'E\',\'R\'];
const array2 = [\'T\',\'A\',\         


        

Answer 1

You could take a closure over the index for the second array and increment the index and remove this item from the result set.

var array1 = ['T', 'E', 'A', 'P', 'A', 'P', 'E', 'R'],
    array2 = ['T', 'A', 'P'],
    result = array1.filter((i => v => array2[i] !== v || !++i)(0));

console.log(result);

A different approach without a predefined order of array2.

var array1 = ['T', 'E', 'A', 'P', 'A', 'P', 'E', 'R'],
    array2 = ['T', 'A', 'P'],
    set2 = new Set(array2)
    result = array1.filter(v => !set2.delete(v));

console.log(result);