# Addition is not working in JavaScript

I am trying to learn Javascript. Here I am confused with the following code.

http://rendera.heroku.com/usercode/eae2b0f40cf503b36ee346f5c511b0e29fc82f9e

When I put `x+y` in the function it is going wrong. For example `2+2=22`, `5+7=57`

But `/`, `*`, `-` are working. Why is `+` not working? Please help me. Thanks a lot in advance

One or both of the variables is a string instead of a number. This makes the `+` do string concatenation.

``````'2' + 2 === '22';  // true

2 + 2 === 4;  // true
``````

The other arithmetic operators `/ * -` will perform a `toNumber` conversion on the string(s).

``````'3' * '5' === 15;  // true
``````

A quick way to convert a string to a number is to use the unary `+` operator.

``````+'2' + 2 === 4;  // true
``````

``````+x + +y
``````

`+` has two uses. One is addition, the other however is string concatenation. If one or both of your variables is a string, then `+` will concatenate them.

You will need to use `parseInt` or `parseFloat` to turn a string into a number.

In Javascript the + operator can either perform addition or concatenation depending on the type of its operands. When numbers are used with + it uses addition, but when strings are used with + it concatenates (joins the strings) instead

this works every time

``````((x*1) + (y*1))
``````

If the numbers that you are trying to add are 10 and 12, if they resulting sum is supposed to be 22, then you should probably do it as

``````+10 + +12
``````

And the result might be a string like 1012 if one or both of the numbers is a string.

Unary plus should work:

``````var totalVal = (+2) + (+2);

// result 4
``````

The addition operator works the following way:
1) If at least one operand is a string, then another is converted to string and concatenation is performed;

``````1 + "2"        // "12"
"2" + "3"      // "23"
"2" + null     // "2null", null is converted to "null"
``````

2) In other cases both operands are converted to numbers:

``````1 + null      // 2, null is converted to 0
1 + undefined // NaN, undefined is converted to NaN
``````

Check the post JavaScript's addition operator demystified for more details.