Saving files is a useful way to store data so it can be viewed after a program has stopped running. The saveStrings() function writes an array of strings to a file, with each string written to a new line. This file is saved to the sketchÕs folder. This example won't work in a web browser because of Java security restrictions.
Original Processing.org Example: SaveFile1
// All Examples Written by Casey Reas and Ben Fry // unless otherwise stated. int[] x = new int[0]; int[] y = new int[0]; void setup() { size(200, 200); } void draw() { background(204); stroke(0); noFill(); beginShape(); for (int i = 0; i < x.length; i++) { vertex(x[i], y[i]); } endShape(); // Show the next segment to be added if (x.length >= 1) { stroke(255); line(mouseX, mouseY, x[x.length-1], y[x.length-1]); } } void mousePressed() { // Click to add a line segment x = append(x, mouseX); y = append(y, mouseY); } void keyPressed() { // Press a key to save the data String[] lines = new String[x.length]; for (int i = 0; i < x.length; i++) { lines[i] = x[i] + "\t" + y[i]; } saveStrings("lines.txt", lines); exit(); // Stop the program }