By the end of this tutorial, you’ll use Lodash’s _.stubFalse() as a named “always false” function—for predicates, mocks, and disabled feature gates.
_.stubFalse()
Any args ignored.
_.stubFalse
Filter / some.
constant(false)
Opposite stub.
_.stubFalse()?_.stubFalse is a zero-argument function that always returns false. It belongs to Lodash’s stub helper family alongside _.stubArray() and _.stubTrue(). Under the hood it is equivalent to _.constant(false).
_.stubFalse() gives you the value false. _.stubFalse (no parentheses) is the function itself—pass it when Lodash or your code expects a predicate callback.
Use it when you need a readable, reusable “never passes” check—clearer than sprinkling () => false through cond tables and filter pipelines.
Invoke with no arguments (they are ignored anyway):
_.stubFalse()_.stubFalse — function reference for predicates and callbacks._.stubFalse() — call once to get boolean false._.stubFalse(1, "x", {}) still returns false._.cond, use _.stubTrue for default branches, not stubFalse.false, not 0 or "".import stubFalse from "lodash/stubFalse";
stubFalse();
// false| Task | Code pattern | Notes |
|---|---|---|
| Get false now | _.stubFalse() | Boolean value |
| Fail predicate | _.filter(arr, _.stubFalse) | Empty result |
| Disabled check | const ok = _.stubFalse | Fn reference |
| Mock validator | validate: _.stubFalse | Always invalid |
| Equivalent | _.constant(false) | Same behavior |
| Default in cond | _.stubTrue | Not stubFalse |
falseBoolean
FunctionZero-arg
IgnoredAlways false
UtilStub
_.stubFalse accepts no meaningful parameters—callers may pass args, but stubFalse ignores them:
arguments IgnoredAny values passed when stubFalse is used as a callback are discarded.
_.stubFalse(1, 2, 3)return falseAlways the boolean primitive false.
falsereference PatternPass _.stubFalse without () to APIs expecting a function.
_.some(arr, _.stubFalse)call once PatternUse _.stubFalse() when you need the value—not a callable function reference.
return _.stubFalse()Need always-true instead? See _.stubTrue()—especially as the default pair in _.cond().
Practical _.stubFalse() patterns with copy-ready code, sample output, and interactive Try It Yourself labs.
Call stubFalse and confirm the result.
The simplest use—evaluate to boolean false.
console.log(_.stubFalse());
console.log(typeof _.stubFalse());
console.log(_.stubFalse() === false);
// false
// "boolean"
// trueSame result as writing false directly—stubFalse names the intent in Lodash-heavy code.
Whether called with zero or many args, the answer is always false.
console.log(_.stubFalse());
console.log(_.stubFalse("anything"));
console.log(_.stubFalse(99, { ok: true }));
// false, false, falseLike _.constant(false), stubFalse never inspects callback arguments from _.filter or _.some.
Predicates, disabled features, and test mocks.
_.stubFalsePass the function reference—every element fails the predicate.
const nums = [1, 2, 3, 4, 5];
console.log(_.filter(nums, _.stubFalse));
console.log(_.some(nums, _.stubFalse));
// []
// falseUseful for temporarily disabling a filter branch while keeping pipeline structure intact.
Store the stub as a callable check— not _.stubFalse() which is just the boolean.
const isFeatureEnabled = _.stubFalse;
if (isFeatureEnabled()) {
console.log("Feature on");
} else {
console.log("Feature off");
}
// Feature offOld tutorials wrote const f = _.stubFalse() then f()—that throws because false is not callable. Assign _.stubFalse instead.
Pass stubFalse where a validation function is expected.
function submitForm(data, validate = _.stubFalse) {
return validate(data);
}
console.log(submitForm({ name: "Ada" }));
// false — validation always failsDefault parameter uses the function reference so callers can swap in a real validator later.
stubFalse vs constant, arrow, and stubTrue.
Pick the right always-false tool—and know when stubTrue fits cond instead.
console.log(_.stubFalse());
console.log(_.constant(false)());
console.log((() => false)());
console.log(_.stubFalse === _.constant(false)); // often true in Lodash
// cond default — use stubTrue, not stubFalse:
// _.cond([[_.stubTrue, () => "default"]])
// false, false, falsestubFalse for never-pass predicates; stubTrue for cond catch-alls; plain false when a function is not required.
_.stubFalse() WorksCall directly or pass _.stubFalse as a callback.
No conditionals—implementation always yields false.
Elements, indexes, or user data passed by iteratees are unused.
Boolean primitive—fails every truthiness check and filter predicate.
_.stubFalse() returns false—do not call the result again as a function.const fn = _.stubFalse (reference)._.cond—use _.stubTrue instead.isAdmin: _.stubFalse() stores boolean false—same as false, not a function._.constant(false) for behavior; stubFalse is more readable in stub-family code._.stubFalse() is a small named helper for “always false”—whether you need a boolean now or a predicate callback that never passes. Pair it with the rest of the stub family for consistent functional style.
Remember the parentheses rule: reference for callbacks, call when you want the value. For catch-all cond branches, reach for stubTrue instead.
_.stubFalse to filter/some when nothing should match() => false in Lodash cond/filter tables_.stubTrue for cond default branchesfalse or _.stubFalse() directly when no callback is neededconst f = _.stubFalse() then call f()_.noop—noop returns undefined, not false_.stubFalse()Use these points for always-false predicates and mocks.
Every call.
CoreRef vs value.
PitfallPredicate.
UsageSame idea.
RelatedOpposite.
CompareLodash pairs _.stubTrue with _.cond for default branches because it always passes—_.stubFalse is the opposite tool for predicates that should never pass, like filtering zero items or stubbing failed validation.
Try basic false returns, ignored arguments, and filter-nothing predicates.
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