String.concat() Concatenate strings
Last updated: 2026-09-09
String.concat() Concatenate strings
concat joins strings into a new one; the + operator or template literals are more common.
| Category | Strings |
|---|---|
| ES version | ES1 |
📝 Syntax
const result = str.concat(str1, str2);⚙️ Parameters
| strN | Strings to concatenate. |
|---|
Returns：The concatenated string.
Mutates the original：No (returns a new value)
▶ Example
Edit the code, press Run, and see the result in the output panel:
Output：
Hello, World!
ab💡 Tip + and template literals are more common than concat.
🌐 Browser support
| Browser |  Chrome |
 Edge |
 Firefox |
 Safari |
 Opera |
|---|---|---|---|---|---|
| String.concat() | ✓ v1 | ✓ v12 | ✓ v1 | ✓ v1 | ✓ v1 |
| Supported by all modern browsers | |||||
🏷️ Related Items
💡 Related Cases
More case studies coming soon — check back later.
📚 Related Tutorials
❓ FAQ
Qconcat or +?
ASame result; + is shorter and coerces types.
QCan concat join numbers?
AYes — numbers are coerced to strings.
QFor heavy concatenation?
APush to an array and join — fastest for many pieces.
