Node.js Buffer.writeUIntBE() Method
Buffer.writeUIntBE() method is used to write the specified bytes using the big-endian format to a Buffer object. It supports up to 6 bytes of accuracy. Its behavior is undefined when you use the value of anything other than an unsigned integer.
Syntax:
Buffer.writeUIntBE( value, offset, byteLength )
Parameters: This method accepts three parameters as mentioned above and described below:
- value: It specifies the number which needs to be written to the Buffer object.
- offset: It specifies the number of bytes to skip before starting to write into the buffer. The value of offset lies 0 <= offset <= buf.length – byteLength.
- byteLength: It specifies the number of bytes to write into the buffer. The value of byteLength lies 0 < byteLength <= 6.
Return value: It returns the offset plus the number of bytes written.
The below examples illustrate the use of Buffer.writeUIntBE() Method in Node.js.
Example 1:
javascript
// Node.js program to demonstrate the // Buffer.writeUIntBE() method // Creating a buffer of size 4 const buffer_1 = Buffer.allocUnsafe(4); // Writes byteLength bytes of value to buf // at the specified offset. buffer_1.writeUIntBE(0x13141516, 0, 4); // Display the result console.log(buffer_1); // Creating a buffer of size 6 const buffer_2 = Buffer.allocUnsafe(6); buffer_2.writeUIntBE(0x131314141515, 0, 6); // Display the result console.log(buffer_2); |
Output:
<Buffer 13 14 15 16> <Buffer 13 13 14 14 15 15>
Example 2:
javascript
// Node.js program to demonstrate the // Buffer.writeUIntBE() method // Creating a buffer of given size const buffer = Buffer.allocUnsafe(8); //Before writing anything console.log("Before filling buffer"); console.log(buffer); // To fill first 6 bytes, take offset 0 // and bytelength 6 console.log("After filling 6 bytes"); buffer.writeUIntBE(0xaa1313147586, 0, 6); console.log(buffer); // To fill next 2 bytes add 6 offset // and bytelength 2 console.log("After filling next 2 bytes"); buffer.writeUIntBE(0x0123, 6, 2) console.log(buffer); |
Output:
Before filling buffer <Buffer 00 00 00 00 00 00 00 00> After filling 6 bytes <Buffer aa 13 13 14 75 86 00 00> After filling next 2 bytes <Buffer aa 13 13 14 75 86 01 23>
Note: The above program will compile and run by using the node index.js command.
Reference: https://nodejs.org/api/buffer.html#buffer_buf_writeuintbe_value_offset_bytelength
Contact Us