By the end of this tutorial, you’ll use Lodash’s _.upperCase() confidently in real JavaScript projects.
Call _.upperCase(string).
Splits compound identifiers into words.
Not the same as native all-caps.
Normalize display headings.
Standardize mixed-case input.
Returns a new string.
_.upperCase()?_.upperCase() converts a string into uppercase words separated by spaces, using lodash word-segmentation rules. Unlike toUpperCase(), it splits compound identifiers like fooBar into FOO BAR—useful for labels, headings, and normalized search keys.
Think of _.upperCase('fooBar') as “turn this identifier into a loud, space-separated label”—not the same as 'fooBar'.toUpperCase().
_.upperCase([string=''])import upperCase from "lodash/upperCase";
const label = upperCase("userProfileId");
// -> "USER PROFILE ID"| Task | Code pattern | Result |
|---|---|---|
| Basic | _.upperCase('hello') | HELLO |
| camelCase | _.upperCase('fooBar') | FOO BAR |
| kebab-case | _.upperCase('foo-bar') | FOO BAR |
| Empty | _.upperCase('') | '' |
| vs toUpper | _.toUpper() | Alias-style |
| Import | import upperCase from 'lodash/upperCase' | Per-method |
NoReturns new string
toUpperCase()Different rules
SPACE SEPWord split
lowerCaseInverse helper
stringOptionalInput to convert (default ''). Coerced to string.
return valueNew stringUppercase words separated by spaces.
word rulesLodashSplits compound identifiers before uppercasing.
related_.lowerCase()Inverse case conversion with same word rules.
Practical _.upperCase() patterns with copy-ready code and interactive Try It Yourself labs.
Core patterns for _.upperCase() with copy-ready code.
Convert hello world to space-separated uppercase words.
const original = "hello world";
console.log(_.upperCase(original));
// -> "HELLO WORLD"Run the Try It editor to experiment with _.upperCase() on your own strings.
Lodash splits camelCase and kebab-case into words before uppercasing.
console.log(_.upperCase("fooBar"));
console.log(_.upperCase("foo-bar"));
// -> "FOO BAR" for bothRun the Try It editor to experiment with _.upperCase() on your own strings.
An empty input returns an empty string without errors.
console.log(_.upperCase(""));
// -> ""Run the Try It editor to experiment with _.upperCase() on your own strings.
Real-world formatting and data-handling scenarios.
Turn internal field keys into readable uppercase labels.
const field = "dateOfBirth";
const label = _.upperCase(field);
console.log(label);Native toUpperCase does not insert spaces between camelCase segments.
const id = "userProfileId";
console.log("upperCase:", _.upperCase(id));
console.log("toUpperCase:", id.toUpperCase());Standardize mixed input before indexing or comparison.
const input = " Mixed-Case Value ";
const key = _.upperCase(input.trim());
console.log(key);_.upperCase() WorksCoerce input (default empty string).
Apply lodash word boundary rules.
Convert each word segment to uppercase.
Return space-separated uppercase words.
_.upperCase() is not identical to String.prototype.toUpperCase().fooBar become FOO BAR, not FOOBAR.'' without error._.upperCase() is your go-to for word-aware ALL CAPS labels from mixed-case or compound identifiers. Remember it differs from native toUpperCase() when strings contain camelCase or separators.
FOO BAR
CoreDifferent rules
CompareIdentifiers → display
Use caseNew string
BasicsNext method
Nav_.upperCase('fooBar') yields FOO BAR while 'fooBar'.toUpperCase() yields FOOBAR—they solve different problems. See also _.toUpper().
Open the Try It editor and run the examples with your own strings.
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