show random image on Processing - image

Question

I'm really noob on processing and programing and I can't figure it out how to show my images at random.
I'm loading the images in setup with the PImage name img0, img1, img2 and then
image("img" + random(3), 0, 0);
But it does't work, coz processing wait for a PImage argument, and the string plus a number isn't.
And I know for shure there must be some better way than:
int randomNumber = random(3);
if(randomNumber == 0 ){
image(img0,0,0);
}
if(randomNumber == 1 ){
image(img1,0,0);
}
if(randomNumber == 2 ){
image(img2,0,0);
}
But I haven't found it.
Any thoughts?
thanks!

Answer 1

In addition to Kevin's great answer you can also use a an array to store the loaded PImages.
Here's a rough example (you'll need to adjust path to images of course):
// total number of images
int numImages = 3;
// an array of images
PImage[] images = new PImage[num];
int randomNumber;
void setup(){
//TODO correct sketch size
size(300,300);
// initialize images array (loading each one)
for(int i = 0 ; i < numImages; i++){
// TODO correct path to images
images[i] = loadImage("img"+(i)+".png");
}
}
void draw(){
background(0);
//render the most recently selected random index image
image(images[randomNumber]);
//instructions
text("click to randomize",10,15);
}
// change the random number on click (draw() would look chaotic/hard to debug)
void mousePressed(){
// pick a random number and cast the floating point value return to integer needed as in images array index
randomNumber = (int)random(numImages);
}

Answer 2

You could use a HashMap to create a map from String keys to PImage values. Something like this:
HashMap<String, PImage> imageMap = new HashMap<String, PImage>();
imageMap.put("image1", image1);
imageMap.put("image2", image2);
Then to get a PImage from a String key, you'd call the get() function:
PImage image1 = imageMap.get("image1");
You can find more info in the reference.
By the way, this line won't compile:
int randomNumber = random(3);
The random() function returns a float value. You can't store a float value in an int variable. You have to convert it using the int() function:
int randomNumber = int(random(3));
If you still can't get it working, please post a MCVE that demonstrates the problem. Good luck.