Logical Operators

[jsartisan]

Info

difficulty: easy
title: Logical Operators
type: quiz
tags: javascript, logical operators

Question

What will the following code snippet log to the console?

let a = 1;
let b = "";
let c = 0;

console.log(a && b && c);
console.log(a || b || c);

Solution

The console output will be:

""
1

Explaination

In the code snippet, we are using the logical AND (&&) and logical OR (||) operators to evaluate expressions involving variables a, b, and c.

1. Logical AND (&&) Operation:

   • The && operator returns the first falsy value it encounters, or the last value if all values are truthy.
   • Here's how a && b && c is evaluated:
     • a is 1, which is truthy.
     • b is "", which is falsy.
     • c is 0, which is falsy.
     • Therefore, a && b && c evaluates to the first falsy value encountered, which is "".
     • So, console.log(a && b && c); logs "".

2. Logical OR (||) Operation:

   • The || operator returns the first truthy value it encounters, or the last value if all values are falsy.
   • Here's how a || b || c is evaluated:
     • a is 1, which is truthy.
     • b is "", which is falsy.
     • c is 0, which is falsy.
     • Therefore, a || b || c evaluates to the first truthy value encountered, which is 1.
     • So, console.log(a || b || c); logs 1.

[github-actions]

#64 - Pull Request updated.