By the end of this tutorial, you’ll reliably test whether strings end with a target suffix using Lodash’s _.endsWith() method.
Call _.endsWith(string, target, position).
Returns true or false—never mutates.
Validate .pdf, .png, and upload rules.
Search only up to an index with the optional third parameter.
Pair with _.startsWith for prefix/suffix checks.
Prefer case normalization when extensions may vary in case.
_.endsWith()?_.endsWith() checks whether a string ends with a given target substring. It returns a boolean—true when the target matches the tail of the string (or the slice up to position), and false otherwise. It mirrors the native String.prototype.endsWith with Lodash’s consistent API and edge-case handling.
Think of _.endsWith(fileName, '.pdf') as “is this a PDF file?” without writing manual slice logic.
Suffix checks appear in upload validators, static asset routers, autocomplete filters, and anywhere you branch logic based on how a path or filename ends.
Provide the haystack string, the suffix to test, and an optional search position:
_.endsWith(string, target, [position=string.length])string — the string to search within.target — the suffix to match at the end (or at position).position — optional index to treat as the effective end of the string.true or false..PDF and .pdf are different; normalize case if needed.import endsWith from "lodash/endsWith";
const fileName = "report.pdf";
const isPdf = endsWith(fileName, ".pdf");
// -> true| Task | Code pattern | Result |
|---|---|---|
| Basic suffix | _.endsWith(str, 'world!') | true/false |
| File extension | _.endsWith(name, '.png') | Image check |
| With position | _.endsWith('abc', 'b', 2) | Search up to index |
| Filter array | items.filter(i => _.endsWith(i, 'i')) | Suffix matches |
| Prefix check | _.startsWith(str, 'http') | Complement helper |
| Native | str.endsWith(target) | ES2015 equivalent |
booleantrue or false
NoRead-only check
_.startsWith()Prefix check
positionCap search index
Every argument to _.endsWith() and what it controls:
string RequiredThe string to inspect. Coerced to string if needed.
_.endsWith('hello!', '!')target RequiredThe substring expected at the end. Empty target matches any string.
_.endsWith(url, '.html')position OptionalIndex treated as the end of the string for matching. Defaults to string.length.
_.endsWith('abc', 'b', 2)return value Booleantrue when the target matches the suffix; otherwise false.
// -> trueFor case-insensitive extension checks, normalize with _.toLower() on both strings first.
Practical _.endsWith() patterns with copy-ready code, sample output, and interactive Try It Yourself labs.
Test whether a string ends with a target suffix.
See whether a phrase ends with world!
import endsWith from "lodash/endsWith";
const str = "Hello, world!";
const match = endsWith(str, "world!");
console.log(match);
// -> trueLodash compares the tail of str against the target length.
Accept only documents ending with .pdf.
import endsWith from "lodash/endsWith";
const fileName = "document.pdf";
const isPdf = endsWith(fileName, ".pdf");
console.log(isPdf);
// -> trueA simple guard for upload validators and download buttons.
Use endsWith inside Array.filter for suffix rules.
import endsWith from "lodash/endsWith";
const items = ["apple", "banana", "kiwi"];
const endsWithI = items.filter((item) => endsWith(item, "i"));
console.log(endsWithI);
// -> ["kiwi"]Boolean helpers compose cleanly with array methods.
Branch routing logic when a path ends with .html.
import endsWith from "lodash/endsWith";
const url = "https://example.com/page.html";
const isHtml = endsWith(url, ".html");
// -> trueThe check looks only at the tail of the URL string—for real routing, combine with the URL API to read pathname safely.
Search only up to a specific index in the string.
import endsWith from "lodash/endsWith";
const value = "abc";
console.log(endsWith(value, "b", 2)); // -> true
console.log(endsWith(value, "c", 2)); // -> falseposition caps how much of the string is considered—only characters before that index participate in the suffix test.
Native equivalents and related helpers.
Modern JavaScript includes the same capability on strings.
import endsWith from "lodash/endsWith";
const str = "archive.zip";
// Lodash
console.log(endsWith(str, ".zip")); // -> true
// Native ES2015
console.log(str.endsWith(".zip")); // -> trueReach for Lodash when you want a consistent functional style across utilities; native is fine in modern runtimes.
_.endsWith() WorksLodash converts string and target to strings.
Use provided position or default to string length.
Consider only characters up to the resolved position.
Match the last target.length characters against target.
true when the suffix matches; false otherwise. No string mutation.
_.endsWith() is case-sensitive unless you normalize case first.target matches any string (same as native behavior).position lets you test prefixes of the string as if they were the full length.false for non-matching suffixes without throwing.lodash/endsWith for tree-shaking._.endsWith() is a focused boolean helper for suffix checks: file types, URL endings, and filtered collections. Keep case normalization in mind and use the position parameter when you need partial-string semantics.
Next, secure your output with _.escape() for HTML entity encoding.
_.endsWith()Use these points whenever you test string suffixes in JavaScript.
Returns true or false.
BasicsValidate file suffixes.
PatternOptional end index.
APICheck prefixes too.
RelatedNext: HTML safety.
Next stepLodash _.endsWith() mirrors native String.prototype.endsWith, including the optional position argument—so _.endsWith('abc', 'b', 2) is true while _.endsWith('abc', 'c', 2) is false. Pair with _.startsWith() for full prefix/suffix checks.
Open the Try It editor, run the examples, and experiment with your own strings.
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