In Nodejs, the **`Buffer.writeIntBE()` method** writes up $48$ bits of `value` to the buffer as a `signed integer`. 

>It writes to the buffer in the Big Endian format.

# 
## Endianness

The **endianness** of data refers to the order of bytes in the data. There are two types of Endianness: 
1. Little Endian 
2. Big Endian.

**Little Endian** stores the *Least Significant Byte (LSB)* first. It is commonly used in Intel processors. 

**Big Endian** stores the *Most Significant Byte (MSB)* first. It is also called the 'Network Byte Order' because most networking standards first expect the *MSB*.

# 
#  Syntax

---
```javascript
buf.writeIntBE(value, offset, byteLength)
```
---

# 
## Parameters

* **`value`**: The value of the unsigned integer to be written to the buffer of the  `BigInt` type.

* **`offset`**: The offset from the starting position where the `value` will be written. The default value for `offset` is $0$. 
  
  The `offset` must be between $0$ and `buffer.length - byteLength`.

* **`byteLength`**: `byteLength` specifies the number of bytes to write to the buffer. The value of `byteLength` must be greater than $0$ and `byteLength <= 6`. 

  It should be less than equal to $6$ because the `Buffer.writeIntBE()` method gives a maximum of 48 bits of accuracy.

##
## Return value

`buffer.writeUIntBE()` returns the offset plus the number of bytes written to the buffer.

const buf = Buffer.alloc(6);
buf.writeIntBE(0x12, 3, 2);
console.log(buf);


# 
## Explanation

We create a buffer called `buf` in the code above and allocate 6 bytes of memory. Then, the `value` `0x12` is written to the buffer at the `offset` 3 and the `byteLength` 2. 

This pads the `value` `0x12` until it takes 2 bytes of memory, making it `0x0012`. 

Hence, when we print the `buf` contents in line $3$, `0x12` prints out at the 4th index instead of the 3rd.

Whats is the Buffer.writeIntBE() method in Nodejs?

Endianness

Syntax

Parameters

Return value

Code

Explanation