The Buffer.concat() function combines multiple instances of buffers into a single buffer and returns it.
The Buffer.concat() function accepts the following parameters:
list: A list of all the buffer instances that the function concatenates.totalLength: The sum of the individual lengths of all the buffers, input to the function as type integer.If list is empty or totalLength is zero, the Buffer.concat() function returns a buffer of zero length.
If totalLength is not input, the Buffer.concat() function deduces the length from the given list. If the actual total length of the buffers is greater than the totalLength, the function truncates the final buffer to fit into the size given by totalLength.
Note: The
Buffer.concat()function convertstotalLengthinto an unsigned integer.
The following code demonstrates how to use the Buffer.concat() function in Node.js.
Buffer.from().buf.length and concatenates the three buffers.// create buffersconst buf1 = Buffer.from("this")console.log(buf1)const buf2 = Buffer.from("is a")console.log(buf2)const buf3 = Buffer.from("test string")console.log(buf3)//calculate total lengthconst len = buf1.length + buf2.length +buf3.lengthconst arr = [buf1, buf2, buf3]//conactenatconst concatbuf = Buffer.concat(arr, len)console.log(concatbuf)
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