emisqwe - 1 year ago 89
Node.js Question

# The + + operator in javascript

When I have one plus, I get the wrong answer e.g.

``````var b = [069];
var total = 0;

total = total + b
console.log(total) // total = 069
``````

However, when I add a second plus so the equation looks like this

``````total = total + + b  // total = 69
``````

I get the correct answer of 69. The above is just a simplified example of my issue.

This works fine, however whilst using JSHint I get a warning saying

``````confusing pluses
``````

How can I get the correct answer without using the + + ? Also, what is this operator called?

Posting my comment as an answer

`+` in front of a variable would cast it to a number if I'm correct.

`"5"` would return `"5"` (string), where
`+"5"` would return `5` (number).
You could use `total = parseInt(total) + parseInt(b);` to get a correct result, as `parseInt()` would try to make a number out of any input parameter it gets.
Theoritecally, you could just parse the `total` as a number, but it would be prone to an error like `"1" + "0" = "10"` resulting in `10`, which should mathematically be `1`.