The Buffer.concat() method is used to concat all buffer objects in a given array into one buffer object. The return value of this method is also a buffer. If the length of the buffer is not provided then it is calculated from the Buffer instances in the list.
Syntax:
Buffer.concat( list, length )
Parameters: This method accepts two parameters as mentioned above and described below:
- list: Contains the list of buffers to concat.
- length: It defines the length of the concatenated buffer. This parameter is optional.
Example 1: In this example, we will see the use of Buffer.concat() method
javascript
// Returns a new buffer with the// copy of the passed stringconst buf1 = Buffer.from("Geeks");
// Returns another buffer with// copy of the passed stringconst buf2 = Buffer.from("for");
const buf3 = Buffer.from("Geeks");
// Creates an array of buffersconst list = [buf1, buf2, buf3];// Concatenates all buffer objects into one bufferconst newbuff = Buffer.concat(list);console.log("The concatenated buffer:");
// Displays the concatenated bufferconsole.log(newbuff); |
Output:
The concatenated buffer: <Buffer 47 65 65 6b 73 66 6f 72 47 65 65 6b 73>
Example 2: In this example, we will see the use of the Buffer.concat() method
javascript
// Returns a new buffer with the// copy of the passed stringconst buf1 = Buffer.from("Good");
// Returns another buffer with// copy of the passed stringconst buf2 = Buffer.from("morning");
const buf3 = Buffer.from("everyone");
// Creates an array of buffersconst list = [buf1, buf2, buf3];// Concatenates all buffer objects// into one bufferconst newbuff = Buffer.concat(list);console.log("The concatenated buffer:");
// Displays the concatenated bufferconsole.log(newbuff); |
Output:
The concatenated buffer: <Buffer 47 6f 6f 64 6d 6f 72 6e 69 6e 67 65 76 65 72 79 6f 6e 65>
Note: The above program will compile and run by using the node index.js command. Reference: https://nodejs.org/dist/latest-v13.x/docs/api/buffer.html#buffer_class_method_buffer_concat_list_totallength