Buffer.alloc function is part of the Buffer module in Node.js and is used to allocate a buffer of any size less than the constant value of
Buffer.alloc(length, value, encoding);
Buffer.alloc function takes up to three arguments:
length: the length of the buffer.
value: the value to be stored in the buffer. The value is replicated to fill the buffer.
encoding: the encoding of the value. If the value is a string, the encoding is assumed to be
utf8 by default.
lengthis a required parameter; the other two are optional parameters.
Buffer.alloc function supports the following encoding types:
If the size of
length is greater than
buffer.constants.MAX_LENGTH or smaller than 0, the error
ERR_INVALID_ARG_VALUE is raised. The function does not return anything otherwise.
The following code snippet below shows how to allocate a buffer of size 15 and in
hex encoding. The value is in base 10. In
hex, 88 converts to 58. The buffer is shown as output in the console, using the
var buf = Buffer.alloc(15, 88, "hex"); console.log(buf);
Here, the prescribed value is of type
string. Hence, the encoding has been selected as
utf-8 by default. Since the value of the character
e is 65 in
hex, the buffer is filled with 20 values of 65. Note that 20 is the prescribed length of the buffer.
var buf = Buffer.alloc(20, 'e'); console.log(buf);
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