Last Modified : Sunday, Aug 18, 2024

JavaScript provides multiple ways to create files programmatically. Here are five common methods:

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1. Using Blob

Blobs are binary large objects that allow you to store file data directly in JavaScript. You can easily create a file using the Blob constructor.

const data = new Blob(["Hello, world!"], { type: "text/plain" });
const file = new File([data], "example.txt");
console.log(file);

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2. Using File Constructor

The File constructor is a more direct way of creating a file from an array of data.

const content = ["JavaScript File Creation"];
const file = new File(content, "file.txt", { type: "text/plain" });
console.log(file);

Accepts file content, name, and type as arguments.

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3. Using FileReader and Blob

You can create a file using FileReader by reading a Blob and converting it to a base64 URL.

const blob = new Blob(["Some content"], { type: "text/plain" });
const reader = new FileReader();
reader.onloadend = () => {
  console.log(reader.result);
};
reader.readAsDataURL(blob);

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4. Using URL.createObjectURL

You can create a downloadable file URL using URL.createObjectURL with a Blob or File.

const blob = new Blob(["Download this content!"], { type: "text/plain" });
const fileURL = URL.createObjectURL(blob);
console.log(fileURL);

Generates a temporary URL to download or use the file created.

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5. Using Streams API

The Streams API allows you to write file data in chunks, perfect for large files or real-time data.

const stream = new WritableStream({
  write(chunk) {
    console.log("Writing chunk:", chunk);
  }
});
const writer = stream.getWriter();
writer.write("Chunk data");
writer.close();

Provides a mechanism to write chunks of data for large file creation or streaming.

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These are quick ways to create files using JavaScript. Depending on your use case, you can pick the method that best suits your needs!