How to compare two array and store the similar element into another array in Javascript?

Question

I wanted to compare two array and store the element that is present in both array into a new array. So I write this code but it didn't work.

    var sampleArray = [1, 2, 3, 4, 5, 6, 7];
var sampleArray2 = [5, 6, 7, 8, 9, 10 ,11];
var similarElements =[];
for (let i = 0; i < sampleArray.length; i++) {
    for (let j = 0; j < sampleArray2.length; j++) {
        if (sampleArray[i] === sampleArray2[j]) {
            similarElements.push();
        }
    }
    
    
    
}
console.log(similarElements);

#evolutionbox im trying to push it into similar elements. Please check the code inside the if statement — Abrar Raem Rifat, May 11 '21 at 13:22
`.push` [expects a value to be passed into it](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push). You're not pushing anything at the moment — evolutionxbox, May 11 '21 at 13:24
Does this answer your question? [How to get the difference between two arrays in JavaScript?](https://stackoverflow.com/questions/1187518/how-to-get-the-difference-between-two-arrays-in-javascript) — Kieran, May 11 '21 at 13:31
#evolutionbox how can i push the result into similiarelements? — Abrar Raem Rifat, May 11 '21 at 13:42

score 1 · Answer 1 · answered May 11 '21 at 13:25

let arr1 = [1, 2, 3, 4, 5, 6, 7];
  arr2 = [5, 6, 7, 8, 9, 10 ,11];
  hash = arr1.reduce((h,e)=> (h[e]=1, h), {}), //iterate first array once
  common = arr2.filter(v=>hash[v]); //iterate secod array once
  
  console.log('Cpmmon elements: ', common);

score 0 · Answer 2 · answered May 11 '21 at 13:26

It searches for itself in sampleArray2, if it finds itself it'll add the number to similarArray

var sampleArray = [1, 2, 3, 4, 5, 6, 7];
var similarArray = [];

for (const num of sampleArray) {
    if (sampleArray2.indexOf(num) {
        similarArray.push(num);
    }
}

score 0 · Answer 3 · answered May 11 '21 at 13:27

0

    var sampleArray = [1, 2, 3, 4, 5, 6, 7];
var sampleArray2 = [5, 6, 7, 8, 9, 10 ,11];
var similarElements =[];
for (let i = 0; i < sampleArray.length; i++) {
    for (let j = 0; j < sampleArray2.length; j++) {
        if (sampleArray[i] === sampleArray2[j]) {
            similarElements.push(sampleArray[i]);
        }
    }
    
    
    
}
console.log(similarElements);

answered May 11 '21 at 13:27

kayuapi_my

498
1
6
9

#kayuapi thanks man – Abrar Raem Rifat May 11 '21 at 13:46

How to compare two array and store the similar element into another array in Javascript?

3 Answers3