Sharp GP2Y0D810Z0F how to use?

http://ieee.ucsd.edu/wiki/_media/projects/micromouse/gp2y0d810z0f.pdf

Thats the data-sheet.

So the question is how can I work with the values? What signal is the sensor giving out when it detects a object? "HIGH" or "LOW"?

I tried this:

int sensorPin = A0;    
int sensorValue = 0;
 
void setup() {
    Serial.begin(9600);
}

void loop() {

  sensorValue = analogRead(sensorPin);    
   
Serial.println(sensorValue);
delay(1000);

it just gives me random numbers between 0 and 1000..... what should i do?

Thanks