console.log()
Writes one or more values to the developer console.
Syntax
console.log(...values)Parameters
| Name | Type | Required | Description |
|---|---|---|---|
values | ...any | No | One or more values to log. Each value is converted to a string representation (objects are shown as inspectable trees in modern browsers). |
Returns
undefined — `console.log()` does not return a useful value.
Examples
console.log("Hello, world!");
Output
Hello, world!
console.log(2 + 2);
Output
4
console.log({ name: "Ada", year: 1815 });
Output
{ name: "Ada", year: 1815 }
console.log("user:", { id: 1, name: "Lin" });
Output
user: { id: 1, name: "Lin" }
Notes
- Most modern browsers also support `%c` format strings for styled
output: `console.log("%cBold", "font-weight: bold")`.
- For tabular data, `console.table()` is usually clearer.
- For errors and warnings, prefer `console.error()` and
`console.warn()` so the message stands out.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 1.0 |
| firefox | 4.0 |
| safari | 3.0 |
| edge | 12 |
| node | 0.10 |