p5.js createWriter() Function

Last Updated : 15 Jul, 2025
The createWriter() function in p5.js is used to create a p5.PrintWriter object that can be used to write or print to various available streams. Syntax: 
createWriter( name, [extension] )
Parameters: This function accepts two parameters as mentioned above and described below.
  • name: It is a string that denotes the name of the file to be created.
  • extension: It is a string that specifies the extension of the file. It is an optional parameter.
Return Value: It returns a p5.PrintWriter object that denotes the writer. The example below illustrates the createWriter() function in p5.js: Example 1: javascript 
let fwriter;

function setup() {
  createCanvas(600, 300);
  textSize(18);

  // Create a textarea for the input of text
  inputArea = createElement("textarea");
  inputArea.position(30, 50);
  inputArea.size(300, 100);

  // Create a button for saving text
  saveBtn = createButton("Save text");
  saveBtn.position(30, 160);
  saveBtn.mousePressed(saveFile);

  // Setup the writer
  fwriter = createWriter("note.txt");

  text("Click on the button below to save the written text", 20, 20);
}

function saveFile() {
  // Get the value of the textarea
  // and split the strings on the basis
  // of the nextline character
  stringList = inputArea.value().split("\n");

  // Save the strings to file
  for (line of stringList) {
    fwriter.print(line);
  }

  // Close the writer
  fwriter.close();

  // Clear the writer
  fwriter.clear();
}
Output: writer-strings Example 2: javascript 
function setup() {
  createCanvas(600, 300);
  textSize(18);

  // Create two inputs for the
  // multiplication table
  multiOf = createInput();
  multiOf.position(250, 50);
  multiOf.size(50);

  multiTo = createInput();
  multiTo.position(250, 80);
  multiTo.size(50);

  // Create a button for saving text
  saveBtn = createButton("Generate and save to file");
  saveBtn.position(30, 120);
  saveBtn.mousePressed(saveFile);

  // Setup the writer
  fwriter = createWriter("tables.txt");
}

function draw() {
  clear();
  text("Fill in the values to generate a multiplication table:", 20, 20);
  text("Multiplication table of", 20, 60);
  text("Multiplication table upto", 20, 90);
}

function saveFile() {
  // Get the value of the two inputs
  // and generate table
  let multipicand = multiOf.value();
  let multiMax = multiTo.value();

  for (let multiplier = 1; multiplier <= multiMax; multiplier++) {
    let textToWrite =
      multipicand + " * " + multiplier + " = " + multipicand * multiplier;

    // Print to the writer
    fwriter.print(textToWrite);
  }

  // Close the writer
  fwriter.close();

  // Clear the writer
  fwriter.clear();
}
Output: writer-tables Online editor: https://editor.p5js.org/ Environment Setup: https://www.geeksforgeeks.org/javascript/p5-js-soundfile-object-installation-and-methods/ Reference: https://p5js.org/reference/#/p5/createWriter
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