CODEWITHSUNDEEP
javascript
GDP2
GDP2

Reputation: 2008

&& / || operator strangeness in JavaScript

So, I was working on a project of mine, when I came across a problem like this:

var one = 1;
var two = 2;
var three = 7;
if (one === 1 || two === 2 && three === 3) {
    console.log("ok"); // prints out ok
}

I'm pretty confused with this since I don't think it should print out "ok". I thought that since the condition after the && operator was false, it shouldn't run, but I'm evidently wrong. Can anyone clarify why it's working?

Upvotes: 1

Views: 73

Answers (1)

esqew
esqew

Reputation: 44699

In Javascript, operators are not just evaluated left-to-right, certain operators have more precedence than others. Those with higher precedence (in this case, the && operator of precedence 13) will be evaluated before others (||, precedence 14).

For your particular case, you need to group your conditionals in order to achieve the functionality you want:

if ((one === 1 || two === 2) && three === 3) {
    console.log("ok"); // prints out ok
}

JSFiddle

Upvotes: 3

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