Example 1: check if 2 arrays are equal javascript
const a = [1, 2, 3];
const b = [4, 5, 6];
const c = [1, 2, 3];
function arrayEquals(a, b) {
return Array.isArray(a) &&
Array.isArray(b) &&
a.length === b.length &&
a.every((val, index) => val === b[index]);
}
arrayEquals(a, b); // false
arrayEquals(a, c); // true
Example 2: 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 3: javascript compare arrays
Array.prototype.equals = function(arr2) {
return (
this.length === arr2.length &&
this.every((value, index) => value === arr2[index])
);
};
[1, 2, 3].equals([1, 2, 3]); // true
[1, 2, 3].equals([3, 6, 4, 2]); // false
Example 4: 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 5: check if 2 arrays are equal javascript
var arraysMatch = function (arr1, arr2) {
// Check if the arrays are the same length
if (arr1.length !== arr2.length) return false;
// Check if all items exist and are in the same order
for (var i = 0; i < arr1.length; i++) {
if (arr1[i] !== arr2[i]) return false;
}
// Otherwise, return true
return true;
};
Example 6: 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)