How to compare two arrays in node js?

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I am having two arrays, how can i compare the two arrays at single shot.

   var arr1= ["a","b","c"];
   var arr2 = ["a","c","d"]

   if(arr1 == arr2){
      console.log(true);
    }else{
      console.log(false);
    }
var arr1 = ["a","b","c"];
var arr2 = ["a","c","d"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        return u === arr2[i];
    })
) {
   console.log(true);
} else {
   console.log(false);
}

Side note for edge cases:

=== is often considered slightly broken for this kind of task because NaN behaves unexpectedly:

var arr1 = ["a",NaN,"b"];
var arr2 = ["a",NaN,"b"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        return u === arr2[i];
    })
) {
   console.log(true);
} else {
   console.log(false);
}

The code above actually logs false because NaN !== NaN. In addition, === can't distinguish +0 from -0. To cover both of these cases, you could use a stronger comparison known as "egal" or "is", which can easily be implemented like so:

function is(a, b) {
    return a === b && (a !== 0 || 1 / a === 1 / b) // false for +0 vs -0
        || a !== a && b !== b; // true for NaN vs NaN
}

var arr1 = ["a",NaN,"b"];
var arr2 = ["a",NaN,"b"];

if (arr1.length == arr2.length
    && arr1.every(function(u, i) {
        // Use "is" instead of "==="
        return is(u, arr2[i]);
    })
) {
   console.log(true);
} else {
   console.log(false);
}

How to compare two arrays in JavaScript?, Node.js | Buffer.compare() Method � strings.Compare() Function in Golang with Examples � How to Compare Equality of Struct, Slice and Map in� In Javascript, to compare two arrays we need to check that the length of both arrays should be same, the objects present in it are of the same type and each item in one array is equal to the counterpart in another array.

I would make use of underscore for this.

var same = (_.difference(arr1, arr2).length == 0)

Comparison of Two arrays Using JavaScript, Step 1: We need to declare the function with two parameters. function compare(arr1,arr2){} Step 2: We need to Initialize an empty array. function compare(arr1,arr2){ const finalarray =[]; } Step 3: We are taking the help of forEach method in Array. protoype. forEach(). Step 4: Returning the final Answer. Now we are writing the compare function it helps us to compare above two arrays. Let’s start. Step 1: We need to declare the function with two parameters. function compare(arr1,arr2){} Step 2: We need to Initialize an empty array. function compare(arr1,arr2){const finalarray =[];}

[ES6]

Top answer is good & enough.

But when you just want to compare its values are same you have to sort it before. here's no need sort code.

if(arr1.length == arr2.length && arr1.every((v) => arr2.indexOf(v) >= 0)) {
    console.log(true);
} else {
    console.log(false);
}

And.. I think using a 'some' instead of 'every' is better.

If those are not same, 'some' gives you a early exit. - very little early but early ;)

if(arr1.length == arr2.length && !arr1.some((v) => arr2.indexOf(v) < 0)) {
    console.log(true);
} else {
    console.log(false);
}

Check if two arrays or objects are equal with JavaScript, call(item1); // If an object or array, compare recursively if (['[object Array]', '[object Object]']. indexOf(itemType) >= 0) { if (! isEqual(item1, item2)) return false; } // Otherwise, do a simple comparison else { // If the two items are not the same type, return false if (itemType !== The above two arrays contain the same number of elements and the exact same values but in a different order. Hence, they are not equal when compared through JSON.stringify(). Lodash. For complex arrays that contain elements in a different order as well as other arrays and objects, we need a more robust solution like the Lodash's _.isEqual() method.

Here's another one, without ES5 every:

function arrEq(arr1, arr2) {
  for (var i = 0; i < arr1.length; i++)
    if (arr1[i] != arr2[i])
      return false;
  return i == arr2.length;
}

Checking if two arrays are equal, The simplest and fastest way to compare two arrays is to convert them both to strings using the JSON.stringify() method and a comparison� The code above generates the following result. We can specify the index of the element where you want to insert a new element. If this element is past the last element, the elements in between are created and initialized with the value undefined :

I wanted to add some modification of the code made by 'Taihwan Hah' but could not leave a comment (the system told me so)

So here is my modifs:

function ArrayEquals(arr1,arr2){
    return arr1.length === arr2.length && !arr1.some((v) => arr2.indexOf(v) < 0) && !arr2.some((v) => arr1.indexOf(v) < 0);
}

basically, I had to check for but array because my arrays do not contains unique numbers.

JavaScript array: Find the difference of two arrays, DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>JS, difference between two arrays</title> </head> <body> </body> </html>. Difference between node.js require and ES6 import and export Given two arrays containing array elements and the task is to check if two arrays contain any common

Node.js Buffer.compare() Method, The compare() method compares two buffer objects and returns a number defining their differences: This method can be used to sort arrays containing buffers. Option 1. Easiest option, works in almost all cases, except that null!==undefined but they both are converted to JSON representation null and considered equal:. function arraysEqual(a1,a2) { /* WARNING: arrays must not contain {objects} or behavior may be undefined */ return JSON.stringify(a1)==JSON.stringify(a2); }

Javascript compare two arrays Code Example, Get code examples like "Javascript compare two arrays" instantly right javascript compare two array elements � node js compare 2 arrays� When comparing two strings, "2" will be greater than "12", because (alphabetically) 1 is less than 2. To secure a proper result, variables should be converted to the proper type before comparison: age = Number(age);

Compare Arrays in JavaScript, Comparing two arrays in JavaScript can be tricky. Here's what you need to know. compare two arrays and return duplicate values. 2. How to Subtract Multiple Objects from an Array with Another array. 0. Find and remove object from array of objects-6.

Comments
  • Possible duplicate of How to compare arrays in JavaScript?
  • Note that this might give the wrong results in case arr1 is shorter then arr2 - try: var arr1 = [ 'a', 'b' ], arr2 = ['a','b','c']; Include a simple length comparison before the every, and you're done: if( arr1.length === arr2.length && arr1.every( ...
  • Very good point, Erwin. I have updated my answer to include the length test you have suggested. Thanks!
  • if the value exists but in different position then will this algorithm still works?
  • This assumes the two arrays are sorted the same way.
  • This is incorrect. _ = require('underscore'); _.difference(["a","c"], ["a","c","d"]).length; returns: 0 Same for lodash.