Array is converted to string while adding elements to it from other array

Question

I'm at the start of the road so bear with me. The issue is presented in the title.The code i'm using is as followed:

var arr = [7, 29, 8, 33, 37, 4, -31, 39, 32, -12, 9];
var even = [];
for (var i = 0; i < arr.length; i++){
        if(arr[i]%2 == 0){
            even += arr[i];
        }
    }
console.log(even.length);

The code should just get the even elements from an array and move it to another. When the code is ran, the variable "even" will hold the elements as "8432" instead of [8, 4, 32], which will give me a wrong result in console at the end: "4" instead of "3". I can't figure it out why would behave like this.

Tim B · Accepted Answer · 2016-04-20 19:10:36Z

3

Try

even.push(arr[i])

instead of

even += arr[i];

See http://www.w3schools.com/jsref/jsref_push.asp for more example

answered Apr 20, 2016 at 19:10

Tim B

1,9811 gold badge22 silver badges22 bronze badges

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

Comments

Jonathan.Brink · Accepted Answer · 2016-04-20 19:10:48Z

1

Use push rather than +=:

even.push(arr[i]);

In JavaScript you can kind of think of arrays as a stack (pushing and popping).

More information

answered Apr 20, 2016 at 19:10

Jonathan.Brink

25.3k20 gold badges85 silver badges127 bronze badges

Comments

zer00ne · Accepted Answer · 2016-04-20 19:12:09Z

1

Store your evens in a variable then push that value into the even array. Try the Snippet, it'll display the results.

SNIPPET

var arr = [7, 29, 8, 33, 37, 4, -31, 39, 32, -12, 9];
var even = [];
for (var i = 0; i < arr.length; i++){
        if(arr[i]%2 == 0){
            var x = arr[i];
            even.push(x)
        }
    }
console.log(even);

<!-- Results pane console output; see http://meta.stackexchange.com/a/242491 -->
<script src="http://gh-canon.github.io/stack-snippet-console/console.min.js"></script>

answered Apr 20, 2016 at 19:12

zer00ne

45.2k6 gold badges50 silver badges82 bronze badges

Comments

Nenad Vracar · Accepted Answer · 2016-04-20 19:14:40Z

1

You can use filter() method

var arr = [7, 29, 8, 33, 37, 4, -31, 39, 32, -12, 9];
var even = arr.filter(function(el) {
  return el % 2 == 0;
});

console.log(even);

answered Apr 20, 2016 at 19:14

Nenad Vracar

122k16 gold badges160 silver badges184 bronze badges

Collectives™ on Stack Overflow

Array is converted to string while adding elements to it from other array

4 Answers 4

Comments

Comments

SNIPPET

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

SNIPPET

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related