Summary - Buffer

Combine Buffer.from, concat and toString to write a base64 converter.

Summary - Buffer

In this group you learned the core tools of buffers: creating a buffer from data with Buffer.from, joining with Buffer.concat, converting to string with toString and taking a portion with subarray.

You can combine these five tools to do a real task. For example, you can turn a string into a buffer, take a portion of it, append another buffer and print the result as text. This is a common pattern used in assembling stream data, joining file pieces or processing text. Now you will combine all pieces in one piece of code.

Exercise Combine subarray and concat

Define const buf = Buffer.from("merhaba");. First print buf.subarray(0, 3).toString(). Then print Buffer.concat([buf, Buffer.from("!")]).toString() on a separate line.

Show example solution

const buf = Buffer.from("merhaba");
console.log(buf.subarray(0, 3).toString());
console.log(Buffer.concat([buf, Buffer.from("!")]).toString());

Test yourself

Match each tool to its role

Buffer.from

Creates a buffer from data
Buffer.concat

Joins buffers
toString

Converts to string
subarray

Returns a view
Which method converts a buffer to a string?
```
buf.toString()
```
- alloc
- toString
- concat
- from
Show answer

toString — toString converts a buffer to a string.

Complete the concat call

Buffer.____([buf, Buffer.from("!")])

Show answer

Buffer.concat([buf, Buffer.from("!")])

Next lesson: process.argv

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