javascript function for comparing arrays [duplicate]

Question

Possible Duplicate:
Using jQuery to compare two arrays

I need a Javascript or jQuery function to determine if an array contains all the values of another array. The second array can have more values than the first.

This should return either true or false. For example.

comparing  array1 = [1,2,3]  and  array2 = [1,2]      should return false

comparing  array1 = [1,2,3]  and  array2 = [1,1,2]    should return false

comparing  array1 = [1,2,3]  and  array2 = [3,2,1]    should return true

comparing  array1 = [1,2,3]  and  array2 = [1,2,1,3]  should return true

Performance is not a concern. Thanks!

Similar question at stackoverflow.com/questions/1773069/…. Those answers helped me with this. — GrantVS
– GrantVS, Commented May 3, 2012 at 0:34

Rene · Accepted Answer · 2012-05-03 00:30:24Z

1

Checks each element in the first array and sees if it exists in the second array.

NB. This is pure javascript, might be an easier way in jQuery.

var notFound = false;

for(var i = 0, len = firstArray.length; i < len; i++){
    if(secondArray.indexOf(firstArray[i]) === -1)
    {
         notFound = true;
         break;
    }
}

if(notFound)
{
    ....
}

answered May 3, 2012 at 0:30

Rene

2664 silver badges9 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Tim Sheiner Over a year ago

Something I just discovered, probably obvious to those with more programming skill is that this will return false if the values in the arrays are different types. I had to add a parseFloat() conversion in creating the second array to make sure both arrays contained numbers.

Rene Over a year ago

This post has some useful information about the uses of === and what it will fail on. stackoverflow.com/questions/359494/… My solution was purely for primitive int types, I can't guarantee it will work for objects, strings etc

snies · Accepted Answer · 2012-05-03 00:38:36Z

0

Update: had read the question too fast, following only works if in same order

function same_elements(array1, array2){  
  var result = true; 
  $(array1).each(function(index, value) {
    if (value != array2[index]) {result = false};
  });
  return result;
}

edited May 3, 2012 at 0:38

answered May 3, 2012 at 0:33

snies

3,5411 gold badge24 silver badges19 bronze badges

2 Comments

Visionary Software Solutions Over a year ago

This doesn't work for array1 = [1,2,3] and array2 = [1,2,1,3]

snies Over a year ago

yeah, just realized the unordered case

Collectives™ on Stack Overflow

javascript function for comparing arrays [duplicate]

2 Answers 2

2 Comments

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Linked

Related