Node.js Buffer.readUInt8() Method

The Buffer.readUInt8() method is used to read an unsigned 8 bit integer from a Buffer object. Syntax:

buffer.readUInt8( offset )

Parameters: This method accepts a single parameter offset which specifies the position of buffer object. It represents the number of bytes to skip before starting to read. The value of offset lies between the range 0 to buffer.length - 1. The default value is 0. Return value: It returns the integer value specified by the offset. Example 1: javascript

// Node.js program to demonstrate the
// buffer.readUInt8() method 
const ob=Buffer.from([1, 2, 3]);

// It reads the first value
console.log(ob.readUInt8(0));

// It reads the second value
console.log(ob.readUInt8(1));

// It throws an error
console.log(ob.readUInt8(4));

Output:

1
2
RangeError [ERR_OUT_OF_RANGE]: The value of "offset" is out of range.
It must be >= 0 and <= 2. Received 3
    at boundsError (internal/buffer.js:53:9)
    at Buffer.readUInt8 (internal/buffer.js:141:5)

Example 2: javascript

// Node.js program to demonstrate the
// buffer.readUInt8() method 
const ob1 = Buffer.from([0X32, 0X44, 0X48]);

// It returns the first value
console.log(ob1.readUInt8(0));

// It returns the third value
console.log(ob1.readUInt8(2));
const t = Buffer.from("abc");

// It returns the ASCII value of 'a'
console.log(t.readUInt8(0));

Output:

68
72
97

Note: The above program will compile and run by using the node index.js command. Reference: https://nodejs.org/api/buffer.html#buffer_buf_readuint8_offset