Linked Questions

edit : Quote removed. is not related to the question. Question How come does it always (when all are truthy) takes the last value ? Examples : f= 1 && 2 && 3 //3 f= 'k' &&...

I got asked this question recently in an interview. I know that in JavaScript evaluation goes left to right. 1&&2 should be false right? I read in another ask here that 1&&2 returns 2....

Here is the function I am working with. I actually found it in React Native documentation : var testFunction = function(word) { return word && '🍕'; } Here is how I am using this function : ...

I had checked for many test cases. It's looking if the first value is true and it's returning the second value. Example: 2 && 5 // --> 5 5 && 10 // --> 10 0 && 2 // --&...

var operand1 = null; var operand2 = true; var booleanOperatorReturnsABoolean = operand1 && operand2; booleanOperatorReturnsABoolean == false || booleanOperatorReturnsABoolean == true Result: ...

I wrote the following Javascript function that is meant to return true when exactly one of the arguments is truthy: function onlyOne( a, b, c) { return (a && !b && !c) || (...

There is one interview question below. The logical AND of two truths should be true. But the output is 3. Why? var a = 2; var b = 3; var c = a && b; // value of c = 3 console.log(...

I understand a||b returns an object, not boolean value. I just can't figure out why javascript gives different results for undefined || "" (result is "") "" || undefined (result is undefined) which I ...

I am trying to figure out why this javascript function returns 0 when this.position.startOffset value is 0 but not when the value is a number other than 0. ready: function() { return (this....

Imagine this simple scenario. I have variable that can be plain JS object with one property, ID, that is a number or obj variable can be null. I have simple test() function that checks if the variable ...

I just ran across this code var someBool = !!(o.a && o.a.t); I was about to remove the double-negation, then realized it forces someBool to be a boolean value... Looking on the MDN, I find ...

I get a boolean return when checking for a falsy value, but not a boolean when checking for a truthy value... I am just getting a string instead. This works. const isFalse = !values.firstName &&...

Let's take a look at this code: var token = (req.body && req.body.access_token) || (req.query && req.query.access_token) || req.headers['x-access-token']; ...

I have something like the following: var val = "string"; var testVal = val && val.length; I would expect testVal to be either true or false but it is the length of the string. Not sure why ...

Related to coerce and default values in JavaScript, given this code: function greet(name){ name = name || ''; console.log("Hello " + name); } greet(); Not given any name as parameter, we have ...