Arduino Uno - Makes an array of 10 LEDs blink systematically in a repeating flow motion

A003-LED-Array-Blink-Flow.ino

const int ledCount = 10;
int ledPins[] = { 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 };

void setup() {
    for (int i = 0; i < ledCount; i++) {
        pinMode(ledPins[i], OUTPUT);
    }
}

void loop() {
    for (int i = 0; i < ledCount; i++) {
        lightLed(i);
    }
    for (int i = ledCount - 1; i > 1; i--) {
        lightLed(i - 1);
    }
}

void lightLed(int ledOn) {
    for (int i = 0; i < ledCount; i++) {
        if (i == ledOn) {
            digitalWrite(ledPins[i], HIGH);
        } else {
            digitalWrite(ledPins[i], LOW);
        }
    }
    delay(100);
}