truthyfalsy

Truthy and falsy are terms used in programming to describe the way values are evaluated in boolean contexts. In many programming languages, a value is considered "truthy" if it evaluates to true when used in a boolean context, and "falsy" if it evaluates to false. This concept is particularly relevant in languages like JavaScript, Python, and Ruby.

In JavaScript, for example, the following values are considered falsy: false, 0, -0, 0n (BigInt zero), "", null, undefined, and NaN. All other values are considered truthy. This includes true, non-zero numbers, non-empty strings, objects, arrays, and functions.

The concept of truthy and falsy values is important for control flow statements like if, while, and for loops, as well as logical operators like && and ||. Understanding how values are evaluated in boolean contexts can help prevent bugs and write more efficient code.

In Python, the concept is similar, but the falsy values are slightly different. In Python, the following values are considered falsy: None, False, 0, 0.0, 0j, "", (), [], and {}. All other values are considered truthy.

In Ruby, the concept is also similar, but the falsy values are slightly different. In Ruby, the following values are considered falsy: false and nil. All other values are considered truthy.

Understanding truthy and falsy values can help programmers write more concise and efficient code, as it allows them to use values directly in boolean contexts without explicitly comparing them to true or false. However, it's important to be aware of the specific falsy values in the programming language being used, as they can vary between languages.