Node.js Buffer.subarray() Method

17 Feb, 2022
The buffer.subarray() method is an inbuilt application programming interface of the buffer module which is used to crop a part of array i.e. create sub-array from an array.Syntax:  
Buffer.subarray( starting_index, ending_index )
Parameters: This method has two parameters as mentioned above and described below:  
starting_index: This parameter specifies an integer value that denotes the starting address of the buffer from where new buffer to start. Its default value is 0.
ending_index: It specifies an integer value that denotes ending address of the buffer up to which the new buffer to be created. The default value is the length of the buffer.
Return Value: This method returns the cropped array. This buffer points to the same memory but with cropped starting and ending indices. If ending_index in the parameter is greater than buffer length then buffer length is taken as ending index.Note: If the new buffer is modified then the same will be reflected in the original buffer as they point to the same memory.Below examples illustrate the use of buffer.subarray() method in Node.js:Example 1:  
javascript
// Node.js program to demonstrate the  // Buffer.subarray() method // Allocating bufferconst buf = Buffer.from('GeeksforGeeks', 'ascii'); // Printing original bufferconsole.log("Original buffer is: " + buf); // Cropping buffer, here starting index// is 5 and ending index is 10cropped_buf = buf.subarray(5, 10); // Printing cropped bufferconsole.log("Cropped buffer is: " + cropped_buf);  // Modifying cropped buffercropped_buf[0] = 70;  // Fcropped_buf[1] = 79;  // Ocropped_buf[2] = 82;  // R // Printing cropped bufferconsole.log("Cropped buffer after modification is: " + cropped_buf); // Printing original bufferconsole.log("Original buffer after modification is: " + buf);
Output:  
Original buffer is: GeeksforGeeks
Cropped buffer is: forGe
Cropped buffer after modification is: FORGe
Original buffer after modification is: GeeksFORGeeks
Example 2:  
javascript
// Node.js program to demonstrate the  // Buffer.subarray() method // Allocating bufferconst buf = Buffer.from('GeeksforGeeks', 'ascii'); // Printing original bufferconsole.log("Original buffer is: " + buf);  // Cropping buffer, here starting index// is -10 and ending index is -1cropped_buf = buf.subarray(-12, -1); // Printing cropped bufferconsole.log("Cropped buffer is:" + cropped_buf);  // Cropping buffer again, here starting// index is -10 and ending index is -5cropped_buf = buf.subarray(-10, -5); // Printing cropped bufferconsole.log("Cropped buffer is: " + cropped_buf);  // Cropping buffer again with no parametercropped_buf = buf.subarray(); // Printing cropped bufferconsole.log("Cropped buffer is: " + cropped_buf);
Output:  
Original buffer is: GeeksforGeeks
Cropped buffer is:eeksforGeek
Cropped buffer is: ksfor
Cropped buffer is: GeeksforGeeks
Note: The above program will compile and run by using the node index.js command.Reference: https://nodejs.org/api/buffer.html#buffer_buf_subarray_start_end 
simranarora5sos
Node.js-Buffer-module
Node.js
Web Technologies
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.