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Truthy


In JavaScript, a truthy value is a value that is considered true when encountered in a Boolean context. All values are truthy unless they are defined as falsy. That is, all values are truthy except false, 0, -0, 0n, "", null, undefined, NaN, and document.all.

JavaScript uses type coercion in Boolean contexts.

Examples of truthy values in JavaScript (which will be coerced to true in boolean contexts, and thus execute the if block):


js
if (true); if ({}); if ([]); if (42); if ("0"); if ("false"); if (new Date()); if (-42); if (12n); if (3.14); if (-3.14); if (Infinity); if (-Infinity);

If the first operand is truthy, the logical AND operator returns the second operand:


js
true && "dog"; // returns "dog" [] && "dog"; // returns "dog"



In this article

See also



See also

Related glossary terms:
Falsy

Type coercion

Boolean


Boolean coercion






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