How to match string values of two arrays using javascript

Question

I have two arrays

var arr1 = ['wq','qw','qq'];
var arr2 = ['wq','wq','wq','qw','qw','qw','qw','qq','qq'];

Below what i did is matching arr1 values with arr2. If the array contains same values i pushed the values into newArr.

var newArr = [];
for (var i=0;i<arr1.length;i++) {
    newArr[i] = [];
}

for (var i=0;i<arr2.length;i++) {
    for (var j=0;j<arr1.length;j++) {
        if (arr2[i].indexOf(arr1[j]) != -1)
            newArr[j].push(arr2[i]);
    }
}
console.log(newArr[1]); //newArr[0] = ['wq','wq','wq'];//In second output array newArr[1] = ['qw','qw','qw','qw'];

Is there any easy way to solve this without using two for loops. Better i need a solution in javascript

can you post the output you are expecting from your example inputs. If its an intersection you are looking for try this: stackoverflow.com/a/1885569/2617732 — rdans
– rdans, Commented Mar 18, 2015 at 17:32
Actually i getting the output but i am using two for loops. how to code it in simple way — htoniv
– htoniv, Commented Mar 18, 2015 at 17:44
Do you need exact match between arrays or if one element is present in both arrays then it qualifies for the new array? — Code Whisperer
– Code Whisperer, Commented Mar 18, 2015 at 17:45

Code Whisperer · Accepted Answer · 2015-03-18 17:46:23Z

1

Maybe use indexOf():

var count = 0;
for (var i = 0; i < arr1.length; i++) {
    if (arr2.indexOf(arr1[i]) != -1) {
        count++;
        // if you just need a value to be present in both arrays to add it
        // to the new array, then you can do it here
        // arr1[i] will be in both arrays if you enter this if clause
    }
}

if (count == arr1.length) {
    // all array 1 values are present in array 2
} else {
    // some or all values of array 1 are not present in array 2
}

edited Mar 18, 2015 at 17:46

answered Mar 18, 2015 at 17:37

Code Whisperer

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Comments

Thalsan · Accepted Answer · 2015-03-19 13:03:45Z

1

Your own way wasn't totally wrong, you just had to check if the element was index of the array and not of an element in the array.

var arr1 = ['wq','qw','qq'];
var arr2 = ['wq','wq','wq','qw','qw','qw','qw','qq','qq'];
var newArr = [];

for (var i in arr1) {
    newArr[i] = [];
}

for (var i in arr2) {
    var j = arr1.indexOf(arr2[i]);
    if (j != -1) {
        newArr[j].push(arr2[i]);
    }
}

This way you removed the nested for loop and it still gives you the result you asked for.

edited Mar 19, 2015 at 13:03

answered Mar 19, 2015 at 12:00

Thalsan

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2 Comments

htoniv Over a year ago

it doesn't showing me the expected output. See i did't get any output in console.log(newArr[0])

Thalsan Over a year ago

My bad, made some last minute changes so forgot to fix it. Editted it, so it should be working.

Ashok Chandrapal · Accepted Answer · 2015-03-18 17:50:48Z

0

var arr1 = ['wq','qw','qq','pppp']; 

var arr2 = ['wq','wq','wq','qw','qw','qw','qw','qq','qq']; 
 


function intersect(a, b) { 

    var d = {}; 

    var results = []; 

    for (var i = 0; i 
        d[b[i]] = true; 

    } 

    for (var j = 0; j 
        if (d[a[j]])  

            results.push(a[j]); 

    } 

    return results; 

} 
 


var result_array = intersect(arr1,arr2); 
 

// result_array will be like you want  ['wq','wq','wq'];

answered Mar 18, 2015 at 17:50

Ashok Chandrapal

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1 Comment

Ashok Chandrapal Over a year ago

you can use above function that will be help

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