Programing Language: Processing 3+

if we have the below function

void drawScore(){

textSize(20);

String toPrint = "Number of shots taken: " + shotsTaken; text(toPrint, width/2-textWidth(toPrint)/2, 50);

}

How to keep track of the score in a global variable? (i.e. keep it visible, and increment it each time we hit the ball)

Need the code line for this