Explain the concept of truthy and falsy values in JavaScript.

In JavaScript, a value is considered truthy if it evaluates to `true` in a Boolean context, and falsy if it evaluates to `false`. The concept of truthy and falsy values is crucial in conditions and logical operations.

Here is a list of falsy values in JavaScript:

1. Falsy Values:

   - `false`: The literal `false`.

   - `0`: The number zero.

   - `-0`: Negative zero.

   - `0n`: BigInt zero.

   - `""` (empty string): An empty string is falsy.

   - `null`: The absence of any object value.

   - `undefined`: A variable that has not been assigned a value.

   - `NaN`: Represents a "Not-a-Number" value.

All other values in JavaScript are truthy. This includes non-empty strings, numbers other than zero, objects, arrays, functions, and any non-falsy value.

Here are a few examples illustrating truthy and falsy values:

// Falsy values

if (false || 0 || "" || null || undefined || NaN) {

    console.log("This will not be executed.");

} else {

    console.log("All values are falsy.");

}

// Truthy values

if (true || 42 || "Hello" || [1, 2, 3] || { key: "value" } || function() { console.log("Hello!"); }) {

    console.log("At least one value is truthy.");

} else {

    console.log("This will not be executed.");

}

Understanding truthy and falsy values is important when working with conditions, especially in `if` statements, ternary operators, and logical operations. For example, you might use the concept of truthy and falsy values to check if a variable has a value before using it to avoid unexpected behaviors.