Java min finder not working

Question

Here are fragments of the code I have so far. My problem is that the min values come up as Integer.MAX_VALUE, instead of the value I want. iSpeedMph and pressure are both one-dimensional integer arrays.

    //calculating mins
    Integer min = Integer.MAX_VALUE;
    int minSpeed = Integer.MAX_VALUE;
    int minPressure = Integer.MAX_VALUE;
    for(i = 0; i < iSpeedMph.length; i++)
    {
        if (min > iSpeedMph[i])
        {
            min = iSpeedMph[i];
            minSpeed = iSpeedMph[i];
        }
    }

    min = Integer.MAX_VALUE;

    for(i = 0; i < pressure.length; i++)
    {
        if (min > pressure[i])
        {
            min = pressure[i];
            minPressure = pressure[i];
        }
    }
...
    System.out.printf("%7s%2s%-9s%4s%8s%5s%13.3s%5s%16.2s\n", "Minimum",  " ", " ", " ", " ", " ", minPressure, " ", minSpeed);

When I print out the last line, the terminal shows 214 for pressure and 21 for speed, which, without the formatting, means that they are both Integer.MAX_VALUE.

Simple mistakes like this one are the most annoying, hand in there! — DonyorM, Nov 12 '15 at 17:39

score 2 · Answer 1 · answered Nov 12 '15 at 17:37

2

You are checking if the current item is greater than the current min, which is Integer.MAX_VALUE, but you want to check if the current item is less than the current min instead, e.g.

if (iSpeedMph[i] < min)

and likewise for the other min determinations.

answered Nov 12 '15 at 17:37

rgettman

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score 2 · Answer 2 · answered Nov 12 '15 at 17:37

2

The test

if (iSpeedMph[i] > min)

always returns false. You have to reverse the comparison.

if (iSpeedMph[i] < min)

or as alternative

if (min > iSpeedMph[i])

answered Nov 12 '15 at 17:37

Davide Lorenzo MARINO

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score 1 · Answer 3 · answered Nov 12 '15 at 17:38

The below condition will never become true for any integer, since min is Integer.MAXVALUE.

if (iSpeedMph[i] > min)

just initialize it 0, to check if you are searching min of all in array or, assign min with first array value and loop the array from 2nd element.

score 0 · Answer 4 · edited May 23 '17 at 12:30

0

if (iSpeedMph[i] > min) how could this give you the new min value?

Also, please use min methods already written for you, e.g. https://stackoverflow.com/a/1658144/499922

edited May 23 '17 at 12:30

Community

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answered Nov 12 '15 at 17:40

billc.cn

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score 0 · Answer 5 · answered Nov 12 '15 at 17:41

As others have pointed out you have the comparison in the if statements wrong. But finding min and max in arrays is very simple with Java 8 streams :

int minSpeed = Arrays.stream(iSpeedMph).min().get();
int minPressure = Arrays.stream(pressure).min().get();

Java min finder not working

5 Answers5