Node.js Buffer.compare() Method

Buffer is a temporary memory storage that stores the data when it is being moved from one place to another. It is like an array of integers. Buffer.compare() method compares the two given buffers. 

Syntax:

buffer1.compare( targetBuffer, targetStart,
            targetEnd, sourceStart, sourceEnd )

Parameters: This method accepts five parameters as mentioned above and described below:

• targetBuffer: This parameter holds the buffer which will be compared with another buffer.
• targetStart: It refers to the starting index from which the elements of the target buffer will begin comparing. Its default value is 0.
• targetEnd: It refers to the index to which the elements of the target buffer will be compared. The default value is 0.
• sourceStart: The index in the input buffer from which the comparing of values will start. The default value is 0.
• sourceEnd: The index in input buffer till which the comparing of values will be done. The default value is buffer.length

Return Value: It returns a number indicating the difference in both buffers. The returns number are:

• 0: If they are equal.
• 1: If buffer1 is higher than buffer2 i.e. if buffer1 should come before buffer2 when sorted.
• -1: If buffer2 is higher than buffer1 i.e. if buffer2 should come before buffer1 when sorted.

Example 1: The below example illustrates the Buffer.compare() Method in Node.js: 

javascript

// Node.js program to demonstrate the
// Buffer.compare() Method

// Creating a buffer
const buffer1 = Buffer.from('Geek');
const buffer2 = Buffer.from('Geek');
const op = Buffer.compare(buffer1, buffer2);
console.log(op);

const buffer1 = Buffer.from('GFG');
const buffer2 = Buffer.from('Python');
const op = Buffer.compare(buffer1, buffer2);
console.log(op);

Output: 

0
-1

Example 2: The below example illustrates the Buffer.compare() Method in Node.js: 

javascript

// Node.js program to demonstrate the
// Buffer.compare() Method

// Creating a buffer
const buffer1 = Buffer.from('2');
const buffer2 = Buffer.from('1');
const buffer3 = Buffer.from('3');
const array = [buffer1, buffer2, buffer3];

// Before sorting
console.log(array);

// After sorting array
console.log(array.sort(Buffer.compare));

Output:

[ <Buffer 32>, <Buffer 31>, <Buffer 33> ]
[ <Buffer 31>, <Buffer 32>, <Buffer 33> ]

Example 3: The below example illustrates the Buffer.compare() Method in Node.js: 

javascript

// Node.js program to demonstrate the
// Buffer.compare() Method

const buffer1 = Buffer.from('GeeksOne');
const buffer2 = Buffer.from('GeekTwo');

// Print: -1 as size of buffer1 starting
// from index 4 is less than buffer2 size
let op = buffer1.compare(buffer2, 4);

// Print: 1 as the size of buffer2 starting
// from index 5 is less than size of buffer1
// starting from 0th index
let op1 = buffer1.compare(buffer2, 0, 7, 5);

console.log(op);
console.log(op1);

Output:

-1
1

Note: The above program will compile and run by using the node index.js command. 

Reference: https://nodejs.org/api/buffer.html#buffer_buf_compare_target_targetstart_targetend_sourcestart_sourceend