Checks if value is null or undefined (nullish). Part of Lodash Lang since 4.0.0 (stable — not deprecated). Note: same idea as value == null — 0, "", false, and NaN are not nil.
Pass the value you want to inspect or convert. Read the return type carefully before you use the result.
Call _.isNil. Start with this line.
_.isNil(value)| Call | What it does |
|---|---|
_.isNil(value) | Primary signature. |
Prefer import isNil from "lodash/isNil" when you want a smaller bundle.
_.isNil(value)| Parameter | Description |
|---|---|
| value | Required. Value to check |
| Return Value | Description |
|---|---|
| * | true if nullish, else false |
null, undefined, NaNOnly the two nullish values return true.
console.log(_.isNil(null)); // true
console.log(_.isNil(void 0)); // true
console.log(_.isNil(NaN)); // falsetrue.undefined → true.false.Keep 0, empty string, and false as real values.
console.log(_.isNil(0)); // false
console.log(_.isNil("")); // false
console.log(_.isNil(false)); // false
console.log(!0); // true // different idea!value treats all falsy as missing — isNil does not.isNil vs isNull vs isUndefinedSplit the two nullish cases when you need the difference.
console.log(_.isNil(null)); // true
console.log(_.isNull(null)); // true
console.log(_.isUndefined(null)); // false
console.log(_.isNil(undefined)); // true
console.log(_.isNull(undefined)); // false
console.log(_.isUndefined(undefined)); // truenull.undefined.Skip work when a field was never set.
function labelOf(user) {
if (_.isNil(user) || _.isNil(user.name)) {
return "(anonymous)";
}
return user.name;
}
console.log(labelOf(null)); // (anonymous)
console.log(labelOf({ name: "Ada" })); // Ada
console.log(JSON.stringify(labelOf({ name: "" }))); // ""null → fallback label."Ada".!user.name when "" is allowed.Replace missing values without wiping 0 or false.
function withDefault(value, fallback) {
return _.isNil(value) ? fallback : value;
}
console.log(withDefault(undefined, 10)); // 10
console.log(withDefault(0, 10)); // 0
console.log(withDefault(null, 10)); // 1010.0.value || fallback, which would replace 0._.isNil is a Lodash 4.x Lang helper (since 4.0.0). It runs anywhere Lodash runs — modern browsers (via CDN or bundle) and Node.js / Bun / Deno with npm install lodash. Native engines express the same idea with value == null or nullish coalescing (??), but not this helper by name.
Available in [email protected] full builds and the lodash/isNil modular import. Works in evergreen browsers and current Node LTS when Lodash is installed.
Bottom line: Safe for production once Lodash is on the page or in your bundle. Prefer import isNil from "lodash/isNil" for smaller builds. Equivalent to value == null as a named function.
Check whether a value is exactly null.
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