Node.js Buffer.writeBigUInt64LE() Method (original) (raw)

Last Updated : 7 Jul, 2020

The Buffer.writeBigUInt64LE() method is an inbuilt application programming interface of class Buffer within the Buffer module which is used to writes little endian 64-bits Big integer value to an allocated buffer at the specified offset.Syntax:

Buffer.writeBigUInt64LE( value, offset )

Parameters:

value: This parameter specifies big integer value to be written to the buffer. It should be a valid 64 bits little endian Big integer value. Behavior is undefined when value is anything other than this.
offset: It specifies the number of bytes to skip before write or simply signify the index in the buffer. The value of offset lies 0 <= offset <= Buffer.length - 8. Its default value is 0.

Return Value: This method returns an unsigned integer value that is the sum of offset and number of bytes written. Below examples illustrate the use of Buffer.writeBigUInt64LE() method in Node.js:Example 1: Filename: index.js

javascript `

// Node.js program to demonstrate the // buffer.writeBigUInt64LE() method const buf = Buffer.allocUnsafe(8);

// Writing big integer value into buffer // by using writeBigUInt64LE() method buf.writeBigUInt64LE(0x01030405060708n, 0);

// display the buffer console.log(buf);

Run the index.js file using the following command:

node index.js

Output:

Example 2: Filename: index.js

javascript `

// Node.js program to demonstrate the // buffer.writeBigUInt64LE() method const buf = Buffer.allocUnsafe(8);

// writing big integer value into buffer // by using writeBigUInt64LE() method buf.writeBigUInt64LE(0xaa03040506efffn, 0);

// Display the buffer console.log(buf);

Run the index.js file using the following command:

node index.js

Output:

Reference:https://nodejs.org/dist/latest-v12.x/docs/api/buffer.html#buffer_buf_writebiguint64le_value_offset