This code section is from the main method of my Annual Fuel Use class. The program projects my annual fuel usage based on at least three fill ups of my car.Here, I am calculating the max and min for distance (which is miles traveled), MPG, and price per gallon.  I'd like a general review.//initialization of array of objectsAnnualFuelUse[] fillUps = {new AnnualFuelUse (1, 1, 6500, 6800, 9.70, 3.11),                          new AnnualFuelUse (2, 10, 6800, 7052, 8.10, 3.08),                          new AnnualFuelUse (3, 20, 7052, 7349, 9.20, 3.15)};//calculate Min and Max for distance, MPG, and price per gallondouble minDist = 0, maxDist = 0;double minMPG = 0.0, maxMPG = 0.0, minPrice = 0.0, maxPrice = 0.0;Double dMin = Double.MAX_VALUE;Double dMax = Double.MIN_VALUE;Double mpgMin = Double.MAX_VALUE;Double mpgMax = Double.MIN_VALUE;Double priceMin = Double.MAX_VALUE;Double priceMax = Double.MIN_VALUE;for (int i = 0; i < fillUps.length; i++) {    if (fillUps[i].getDist() < dMin){        dMin = fillUps[i].getDist();        minDist = dMin;    }         if (fillUps[i].getDist() > dMax) {        dMax = fillUps[i].getDist();        maxDist = dMax;    }    if (fillUps[i].getMilesPerGallon() < mpgMin) {        mpgMin = fillUps[i].getMilesPerGallon();        minMPG = mpgMin;    }        if (fillUps[i].getMilesPerGallon() > mpgMax) {        mpgMax = fillUps[i].getMilesPerGallon();        maxMPG = mpgMax;    }                 if (fillUps[i].getPrice() < priceMin) {        priceMin = fillUps[i].getPrice();        minPrice = priceMin;    }              if (fillUps[i].getPrice() > priceMax) {        priceMax = fillUps[i].getPrice();        maxPrice = priceMax;    }}
Calculating min and max with if-statements within a for-loop
java;object oriented
Each and every one of your if-statements can be simplified.if (fillUps[i].getDist() > dMin){    dMin = fillUps[i].getDist();    minDist = dMin;}First of all, since you modify two variables at the same time, you can write it on the same line.if (fillUps[i].getDist() > dMin){    minDist = dMin = fillUps[i].getDist();}However, this is a sign that you might have too many variables, since minDist is the same as dMin. I would keep the variables of primitive type double and get rid of the not-primitive variables. Since Double.MAX_VALUE and Double.MIN_VALUE is a regular double, I don't see the need for the Double type. Just be sure to initialize your min/max variables properly (Double.MIN_VALUE or Double.MAX_VALUE).And then, what you are doing is to always get the minimum of two values, so this can be simplified by using the Math.min method.minDist = Math.min(fillUps[i].getDist(), minDist);So each of your four-line if-statement segments can each become one line!for (int i = 0; i < fillUps.length; i++) {    minDist = Math.min(fillUps[i].getDist(), minDist);    maxDist = Math.max(fillUps[i].getDist(), maxDist);    minMPG = Math.min(fillUps[i].getMilesPerGallon(), minMPG);    maxMPG = Math.max(fillUps[i].getMilesPerGallon(), maxMPG);    minPrice = Math.min(fillUps[i].getPrice(), minPrice);    maxPrice = Math.max(fillUps[i].getPrice(), maxPrice);}