# Java Selection sort example

Selection sort is an in-place comparison sort. It loops and find the first smallest value, swaps it with the first element; loop and find the second smallest value again, swaps it with the second element, repeats third, fourth, fifth smallest values and swaps it, until everything is in correct order.

*P.S Selection sort is inefficient on large lists*

## 1. Explanation

#unsorted data -> [10, 8, 99, 7, 1, 5, 88, 9] #1 -> [10, 8, 99, 7, 1, 5, 88, 9] -> [1, 8, 99, 7, 10, 5, 88, 9] #2 -> [1, 8, 99, 7, 10, 5, 88, 9] -> [1, 5, 99, 7, 10, 8, 88, 9] #3 -> [1, 5, 99, 7, 10, 8, 88, 9] -> [1, 5, 7, 99, 10, 8, 88, 9] #4 -> [1, 5, 7, 99, 10, 8, 88, 9] -> [1, 5, 7, 8, 10, 99, 88, 9] #5 -> [1, 5, 7, 8, 10, 99, 88, 9] -> [1, 5, 7, 8, 9, 99, 88, 10] #6 -> [1, 5, 7, 8, 9, 99, 88, 10] -> [1, 5, 7, 8, 9, 10, 88, 99] #7 -> [1, 5, 7, 8, 9, 10, 88, 99] -> [1, 5, 7, 8, 9, 10, 88, 99] #result : [1, 5, 7, 8, 9, 10, 88, 99]

Here’s the Java Selection sort implementation.

```
public static void sort(int[] input) {
int inputLength = input.length;
for (int i = 0; i < inputLength - 1; i++) {
int min = i;
// find the first, second, third, fourth... smallest value
for (int j = i + 1; j < inputLength; j++) {
if (input[j] < input[min]) {
min = j;
}
}
// swaps the smallest value with the position 'i'
int temp = input[i];
input[i] = input[min];
input[min] = temp;
//next pls
}
}
```

## 2. Java Selection sort example

A full example to demonstrate the use of Selection sort algorithm to sort a simple data set.

SelectionSortExample.java

```
package com.mkyong;
import java.util.Arrays;
public class SelectionSortExample {
public static void main(String[] args) {
int[] array = {10, 8, 99, 7, 1, 5, 88, 9};
selection_sort(array);
System.out.println(Arrays.toString(array));
}
private static void selection_sort(int[] input) {
int inputLength = input.length;
for (int i = 0; i < inputLength - 1; i++) {
int min = i;
// find the first, second, third, fourth... smallest value
for (int j = i + 1; j < inputLength; j++) {
if (input[j] < input[min]) {
min = j;
}
}
// swaps the smallest value with the position 'i'
int temp = input[i];
input[i] = input[min];
input[min] = temp;
//next pls
}
}
}
```

Output

```
[1, 5, 7, 8, 9, 10, 88, 99]
```

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