Example 1: javascript compare two arrays of objects get same elements
var result = result1.filter(function (o1) {
return result2.some(function (o2) {
return o1.id === o2.id; // return the ones with equal id
});
});
// if you want to be more clever...
let result = result1.filter(o1 => result2.some(o2 => o1.id === o2.id));
Example 2: javascript find matching elements in two arrays
const intersection = array1.filter(element => array2.includes(element));
Example 3: best way compare arrays javascript
// To compare arrays (or any other object):
// Simple Array Example:
const array1 = ['potato', 'banana', 'soup']
const array2 = ['potato', 'orange', 'soup']
array1 === array2;
// Returns false due to referential equality
JSON.stringify(array1) === JSON.stringify(array2);
// Returns true
// Another Example:
const deepArray1 = [{test: 'dummy'}, [['woo', 'ya'], 'weird']]
const deepArray2 = [{test: 'dummy'}, [['woo', 'ya'], 'weird']]
deepArray1 === deepArray2;
// Returns false due to referential equality
JSON.stringify(deepArray1) === JSON.stringify(deepArray2);
// Returns true
Example 4: how to compare two arrays javascript
function arraysAreIdentical(arr1, arr2){
if (arr1.length !== arr2.length) return false;
for (var i = 0, len = arr1.length; i < len; i++){
if (arr1[i] !== arr2[i]){
return false;
}
}
return true;
}
Example 5: compare arrays javascript
// For regular 1D array
const array1 = [1,2,3,4]
const array2 = [1,2,3,4]
array1.join() === array2.join()
// '1,2,3,4' === '1,2,3,4'
// For anything more complex
const array3 = [1,2,3,[1,2,3]]
const array4 = [1,2,3,[1,2,3]]
JSON.stringify(array3) === JSON.stringify(array4)
Example 6: javascript find matching elements in two arrays
let firstArray = ["One", "Two", "Three", "Four", "Five"];
let secondArray = ["Three", "Four"];
let map = {};
firstArray.forEach(i => map[i] = false);
secondArray.forEach(i => map[i] === false && (map[i] = true));
let jsonArray = Object.keys(map).map(k => ({ name: k, matched: map[k] }));