concat
fun concat(list: ReadonlyArray<Uint8Array<*>>, totalLength: Number = definedExternally): Buffer(source)
Returns a new Buffer
which is the result of concatenating all the Buffer
instances in the list
together.
If the list has no items, or if the totalLength
is 0, then a new zero-length Buffer
is returned.
If totalLength
is not provided, it is calculated from the Buffer
instances in list
by adding their lengths.
If totalLength
is provided, it is coerced to an unsigned integer. If the combined length of the Buffer
s in list
exceeds totalLength
, the result is truncated to totalLength
.
import { Buffer } from 'node:buffer';
// Create a single `Buffer` from a list of three `Buffer` instances.
const buf1 = Buffer.alloc(10);
const buf2 = Buffer.alloc(14);
const buf3 = Buffer.alloc(18);
const totalLength = buf1.length + buf2.length + buf3.length;
console.log(totalLength);
// Prints: 42
const bufA = Buffer.concat([buf1, buf2, buf3], totalLength);
console.log(bufA);
// Prints: <Buffer 00 00 00 00 ...>
console.log(bufA.length);
// Prints: 42
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Buffer.concat()
may also use the internal Buffer
pool like Buffer.allocUnsafe()
does.
Since
v0.7.11
Parameters
list
List of Buffer
or {@link Uint8Array} instances to concatenate.
totalLength
Total length of the Buffer
instances in list
when concatenated.