How do I make a variable randomly equal 1 of 2 numbers? (Processing) - processing

Question

I'm trying for the first time to make Pong. I don't always want the ball to go to the bottom right by adding 3 every single time. How would I make it so it will either do 3, or -3, but no number in between? I know that "||" doesn't work for integers, and "random(-3,3) has the chance of giving me numbers like "0.1" which wouldn't really function in here.
Code:
float circleX = 640/2;
float circleY = 360/2;
float xSpeed = 3;
float ySpeed = 3;
float Color = (255);
float circleHeight = 32;
float circleWidth = 32;
float xAcceleration = -1.0;
float yAcceleration = -1.0;
float paddleColor = 255;
float MyPaddleX = 630;
float OpPaddleX = 10;
float MyPaddleWidth = 10;
float OpPaddleWidth = -10;
void setup() {
size(640, 360);
frameRate(60);
}
void draw() {
background(0);
//Ball
fill(Color);
ellipse(circleX, circleY, circleWidth, circleHeight);
xSpeed = //(WHAT TO PUT HERE?)
circleX = circleX + xSpeed;
circleY = circleY + ySpeed;
//My Paddle
fill(paddleColor);
rect(MyPaddleX,mouseY,MyPaddleWidth,100);
//Bouncing
if (circleX >= OpPaddleX && OpPaddleX + OpPaddleWidth >= circleX) {
xSpeed = xSpeed * xAcceleration;
}
// Top/Bottom Bouncing
if (circleY > height || circleY < 0) {
ySpeed = ySpeed * yAcceleration;
}
//My Paddle Bounceback
if (circleY >= mouseY && circleY <= mouseY + 100) {
if (circleX >= MyPaddleX && circleX <= MyPaddleX + 3)
xSpeed = xSpeed * xAcceleration;
}
//Opponent Paddle
fill(paddleColor);
rect(OpPaddleX,circleY - 50,OpPaddleWidth,100);
//if (circleX < OpPaddleX || circleX > MyPaddleX) {
// circleX = width/2;
// circleY = height/2;
// xSpeed = 0;
// ySpeed = 0;
//}
}

Answer 1

You can generate a number between 0 and 1 and then compare that generated number to 0.5 to "flip a coin" in your code.
Think about it this way: when you call random(1), you'll get a value between 0 and 1. Half of those values will be less than 0.5, the other half will be greater than (or equal to) 0.5.
So you can do something like this:
float x;
if(random(1) < .5){
x = -3;
}
else{
x = 3;
}
You could expand this to choose from more numbers using else if statements, or you could shorten it into a single line of code using the ternary operator:
float x = random(1) < .5 ? 3 : -3;