Method for finding the closest to a value from an array?

Question

Say:
int val is a number and i need to search through an array, int arr[] for the value closest to val.

but also depending on another value,
int c ,which determines closest, second closest, third closest, etc. to val

How can i write code for this?

Answer 1

Example:
Array: 12,34,1,5,3
val = 7

|7-12| = 5
|7-34| = 27
|7-1| = 6
|7-5| = 2
|7- 3| = 4

--> 5 is closest to 7

abs of a value: Math.abs()
Use a for loop to calc Math.abs(val - arr[i])

Maybe you should store the abs values into another array.

Only the closest:

int min = (int)Math.abs(val - arr[0]);
int c = arr[0];

for(int i = 1; i < arr.length; i++){
if(min > Math.abs(val - arr[i]){
min = (int)Math.abs(val - arr[i]);
c = arr[i];
}
}

Answer 2

if you are more advanced:

add numbers to Integer[] array arr
write your own Comparator<Integer> where
compare abs(v-n1) - abs(v-n2)

sort array with your comparator comp
Arrays.sort(arr, comp)

if v=4
for numbers {7, 8, 2, 3, 6, 4, 5, 9, 1}
you get [4, 3, 5, 2, 6, 7, 1, 8, 9]
where
4 is 1 closest to 4
3,5 are 2 closest
2,6 are 3 closest
...