get closest value to a number in array

Question

I have an array of positive/negative ints

int[] numbers = new int[10]; numbers[0] = 100; numbers[1] = -34200; numbers[2] = 3040; numbers[3] = 400433; numbers[4] = 500; numbers[5] = -100; numbers[6] = -200; numbers[7] = 532; numbers[8] = 6584; numbers[9] = -945; 

Now, I would like to test another int against this array, and return the number that is closest to the int.

For example if I used the number 490 i would get back item #4 from numbers 500 what is the best way to do something like this?

int myNumber = 490; int distance = 0; int idx = 0; for(int c = 0; c < numbers.length; c++){     int cdistance = numbers[c] - myNumber;     if(cdistance < distance){         idx = c;         distance = cdistance;     } } int theNumber = numbers[idx]; 

That doesn't work. Any suggestions on a good method to do this?

Answer 1

int myNumber = 490; int distance = Math.abs(numbers[0] - myNumber); int idx = 0; for(int c = 1; c < numbers.length; c++){     int cdistance = Math.abs(numbers[c] - myNumber);     if(cdistance < distance){         idx = c;         distance = cdistance;     } } int theNumber = numbers[idx]; 

Always initialize your min/max functions with the first element you're considering. Using things like Integer.MAX_VALUE or Integer.MIN_VALUE is a naive way of getting your answer; it doesn't hold up well if you change datatypes later (whoops, MAX_LONG and MAX_INT are very different!) or if you, in the future, want to write a generic min/max method for any datatype.